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Robert Calderbank

Charles S. Sydnor Distinguished Professor of Computer Science
Computer Science
Campus Box 90984, 140 Science Drive, Durham, NC 27708
140 Science Drive, 317 Gross Hall, Durham, NC 27708

Selected Publications


Geometric Matrix Completion With Deep Conditional Random Fields.

Journal Article IEEE transactions on neural networks and learning systems · September 2020 The problem of completing high-dimensional matrices from a limited set of observations arises in many big data applications, especially recommender systems. The existing matrix completion models generally follow either a memory- or a model-based approach, ... Full text Cite

A Characterization of Guesswork on Swiftly Tilting Curves

Journal Article IEEE Transactions on Information Theory · May 1, 2019 Given a collection of strings, each with an associated probability of occurrence, the guesswork of each of them is their position in a list ordered from most likely to least likely, breaking ties arbitrarily. The guesswork is central to several application ... Full text Cite

Multi-Scale Spectrum Sensing in Dense Multi-Cell Cognitive Networks

Journal Article IEEE Transactions on Communications · April 1, 2019 Multi-scale spectrum sensing is proposed to overcome the cost of full network state information on the spectrum occupancy of primary users (PUs) in dense multi-cell cognitive networks. Secondary users (SUs) estimate the local spectrum occupancies and aggre ... Full text Cite

Throughput region of spatially correlated interference packet networks

Journal Article IEEE Transactions on Information Theory · February 1, 2019 In multi-user wireless packet networks, interference, typically modeled as packet collision, is the throughput bottleneck. Users become aware of the interference pattern via feedback and use this information for contention resolution and packet retransmiss ... Full text Cite

LDMNet: Low Dimensional Manifold Regularized Neural Networks

Journal Article Proceedings of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition · December 14, 2018 Deep neural networks have proved very successful on archetypal tasks for which large training sets are available, but when the training data are scarce, their performance suffers from overfitting. Many existing methods of reducing overfitting are data-inde ... Full text Cite

Regularizing autoencoder-based matrix completion models via manifold learning

Conference European Signal Processing Conference · November 29, 2018 Autoencoders are popular among neural-network-based matrix completion models due to their ability to retrieve potential latent factors from the partially observed matrices. Nevertheless, when training data is scarce their performance is significantly degra ... Full text Cite

Extending flash lifetime in embedded processors by expanding analog choice

Journal Article IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems · November 1, 2018 We extend the lifetime of Flash memory in embedded processors by exploiting the fact that data from sensors is inherently analog. Prior work in the computer architecture community has assumed that all data is digital and has overlooked the opportunities av ... Full text Cite

Classifying Pump-Probe Images of Melanocytic Lesions Using the WEYL Transform

Conference ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · September 10, 2018 Diagnosis of melanoma is fraught with uncertainty, and discordance rates among physicians remain high because of the lack of a definitive criterion. Motivated by this challenge, this paper first introduces the Patch Weyl transform (PWT), a 2-dimensional va ... Full text Cite

Synthesis of Logical Clifford Operators via Symplectic Geometry

Journal Article IEEE International Symposium on Information Theory - Proceedings · August 15, 2018 Quantum error-correcting codes can be used to protect qubits involved in quantum computation. This requires that logical operators acting on protected qubits be translated to physical operators (circuits) acting on physical quantum states. We propose a mat ... Full text Cite

Compressed Neighbour Discovery using Sparse Kerdock Matrices

Conference IEEE International Symposium on Information Theory - Proceedings · August 15, 2018 We study the network-wide neighbour discovery problem in wireless networks in which each node in a network must discovery the network interface addresses (NIAs) of its neighbour. We work within the rapid on-off division duplex framework proposed by Guo and ... Full text Cite

ARQ for Interference Packet Networks

Conference IEEE International Symposium on Information Theory - Proceedings · August 15, 2018 In multi-user wireless packet networks interference is the throughput bottleneck. Users become aware of the interference pattern via feedback and use this information for contention resolution and for packet retransmission. We consider networks with spatia ... Full text Cite

Sparse near-equiangular tight frames with applications in full duplex wireless communication

Conference 2017 IEEE Global Conference on Signal and Information Processing, GlobalSIP 2017 - Proceedings · March 7, 2018 We construct extremely sparse, near-equiangular tight frames which share the same row space as certain incomplete Delsarte-Goethals frames. Frames combining these properties have application in full duplex communication in ad-hoc wireless networks. We high ... Full text Cite

DCFNet: Deep Neural Network with Decomposed Convolutional Filters

Journal Article 35th International Conference on Machine Learning, ICML 2018 · January 1, 2018 Filters in a Convolutional Neural Network (CNN) contain model parameters learned from enormous amounts of data. In this paper, we suggest to decompose convolutional filters in CNN as a truncated expansion with pre-fixed bases, namely the Decomposed Convolu ... Open Access Cite

Jenga: Efficient fault tolerance for stacked DRAM

Conference Proceedings - 35th IEEE International Conference on Computer Design, ICCD 2017 · November 22, 2017 In this paper, we introduce Jenga, a new scheme for protecting 3D DRAM, specifically high bandwidth memory (HBM), from failures in bits, rows, banks, channels, dies, and TSVs. By providing redundancy at the granularity of a cache block rather than across b ... Full text Cite

Orthogonal Time Frequency Space (OTFS) modulation for millimeter-wave communications systems

Conference IEEE MTT-S International Microwave Symposium Digest · October 4, 2017 Due to the increased demand for data rate, flexibility, and reliability of 5G cellular systems, new modulation formats need to be considered. A recently proposed scheme, Orthogonal Time Frequency Space (OTFS), offers various advantages in particular in env ... Full text Cite

Rate optimal binary linear locally repairable codes with small availability

Conference IEEE International Symposium on Information Theory - Proceedings · August 9, 2017 A locally repairable code with availability has the property that every code symbol can be recovered from multiple, disjoint subsets of other symbols of small size. In particular, a code symbol is said to have (r, t)-availability if it can be recovered fro ... Full text Cite

Multi-scale spectrum sensing in small-cell mm-wave cognitive wireless networks

Conference IEEE International Conference on Communications · July 28, 2017 In this paper, a multi-scale approach to spectrum sensing in cognitive cellular networks is proposed. In order to overcome the huge cost incurred in the acquisition of full network state information, a hierarchical scheme is proposed, based on which local ... Full text Cite

Multi-scale spectrum sensing in millimeter wave cognitive networks

Conference Conference Record of 51st Asilomar Conference on Signals, Systems and Computers, ACSSC 2017 · July 2, 2017 In this paper, a multi-scale approach to spectrum sensing and information exchange in millimeter wave cognitive cellular networks is proposed. In order to overcome the huge energy cost of acquiring full network state information on the occupancy of each ce ... Full text Cite

Run-length limited codes for backscatter communication

Conference ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · June 16, 2017 In backscatter communications, ultra-low power devices signal by modulating the reflection of radio frequency signals emitted from an external source. Unlike conventional one-way communication, the backscatter channel experiences unique self-interference a ... Full text Cite

Information-Theoretic Compressive Measurement Design.

Journal Article IEEE transactions on pattern analysis and machine intelligence · June 2017 An information-theoretic projection design framework is proposed, of interest for feature design and compressive measurements. Both Gaussian and Poisson measurement models are considered. The gradient of a proposed information-theoretic metric (ITM) is der ... Full text Cite

Geometric Matrix Completion With Deep Conditional Random Fields.

Journal Article IEEE transactions on neural networks and learning systems · September 2020 The problem of completing high-dimensional matrices from a limited set of observations arises in many big data applications, especially recommender systems. The existing matrix completion models generally follow either a memory- or a model-based approach, ... Full text Cite

A Characterization of Guesswork on Swiftly Tilting Curves

Journal Article IEEE Transactions on Information Theory · May 1, 2019 Given a collection of strings, each with an associated probability of occurrence, the guesswork of each of them is their position in a list ordered from most likely to least likely, breaking ties arbitrarily. The guesswork is central to several application ... Full text Cite

Multi-Scale Spectrum Sensing in Dense Multi-Cell Cognitive Networks

Journal Article IEEE Transactions on Communications · April 1, 2019 Multi-scale spectrum sensing is proposed to overcome the cost of full network state information on the spectrum occupancy of primary users (PUs) in dense multi-cell cognitive networks. Secondary users (SUs) estimate the local spectrum occupancies and aggre ... Full text Cite

Throughput region of spatially correlated interference packet networks

Journal Article IEEE Transactions on Information Theory · February 1, 2019 In multi-user wireless packet networks, interference, typically modeled as packet collision, is the throughput bottleneck. Users become aware of the interference pattern via feedback and use this information for contention resolution and packet retransmiss ... Full text Cite

LDMNet: Low Dimensional Manifold Regularized Neural Networks

Journal Article Proceedings of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition · December 14, 2018 Deep neural networks have proved very successful on archetypal tasks for which large training sets are available, but when the training data are scarce, their performance suffers from overfitting. Many existing methods of reducing overfitting are data-inde ... Full text Cite

Regularizing autoencoder-based matrix completion models via manifold learning

Conference European Signal Processing Conference · November 29, 2018 Autoencoders are popular among neural-network-based matrix completion models due to their ability to retrieve potential latent factors from the partially observed matrices. Nevertheless, when training data is scarce their performance is significantly degra ... Full text Cite

Extending flash lifetime in embedded processors by expanding analog choice

Journal Article IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems · November 1, 2018 We extend the lifetime of Flash memory in embedded processors by exploiting the fact that data from sensors is inherently analog. Prior work in the computer architecture community has assumed that all data is digital and has overlooked the opportunities av ... Full text Cite

Classifying Pump-Probe Images of Melanocytic Lesions Using the WEYL Transform

Conference ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · September 10, 2018 Diagnosis of melanoma is fraught with uncertainty, and discordance rates among physicians remain high because of the lack of a definitive criterion. Motivated by this challenge, this paper first introduces the Patch Weyl transform (PWT), a 2-dimensional va ... Full text Cite

Synthesis of Logical Clifford Operators via Symplectic Geometry

Journal Article IEEE International Symposium on Information Theory - Proceedings · August 15, 2018 Quantum error-correcting codes can be used to protect qubits involved in quantum computation. This requires that logical operators acting on protected qubits be translated to physical operators (circuits) acting on physical quantum states. We propose a mat ... Full text Cite

Compressed Neighbour Discovery using Sparse Kerdock Matrices

Conference IEEE International Symposium on Information Theory - Proceedings · August 15, 2018 We study the network-wide neighbour discovery problem in wireless networks in which each node in a network must discovery the network interface addresses (NIAs) of its neighbour. We work within the rapid on-off division duplex framework proposed by Guo and ... Full text Cite

ARQ for Interference Packet Networks

Conference IEEE International Symposium on Information Theory - Proceedings · August 15, 2018 In multi-user wireless packet networks interference is the throughput bottleneck. Users become aware of the interference pattern via feedback and use this information for contention resolution and for packet retransmission. We consider networks with spatia ... Full text Cite

Sparse near-equiangular tight frames with applications in full duplex wireless communication

Conference 2017 IEEE Global Conference on Signal and Information Processing, GlobalSIP 2017 - Proceedings · March 7, 2018 We construct extremely sparse, near-equiangular tight frames which share the same row space as certain incomplete Delsarte-Goethals frames. Frames combining these properties have application in full duplex communication in ad-hoc wireless networks. We high ... Full text Cite

DCFNet: Deep Neural Network with Decomposed Convolutional Filters

Journal Article 35th International Conference on Machine Learning, ICML 2018 · January 1, 2018 Filters in a Convolutional Neural Network (CNN) contain model parameters learned from enormous amounts of data. In this paper, we suggest to decompose convolutional filters in CNN as a truncated expansion with pre-fixed bases, namely the Decomposed Convolu ... Open Access Cite

Jenga: Efficient fault tolerance for stacked DRAM

Conference Proceedings - 35th IEEE International Conference on Computer Design, ICCD 2017 · November 22, 2017 In this paper, we introduce Jenga, a new scheme for protecting 3D DRAM, specifically high bandwidth memory (HBM), from failures in bits, rows, banks, channels, dies, and TSVs. By providing redundancy at the granularity of a cache block rather than across b ... Full text Cite

Orthogonal Time Frequency Space (OTFS) modulation for millimeter-wave communications systems

Conference IEEE MTT-S International Microwave Symposium Digest · October 4, 2017 Due to the increased demand for data rate, flexibility, and reliability of 5G cellular systems, new modulation formats need to be considered. A recently proposed scheme, Orthogonal Time Frequency Space (OTFS), offers various advantages in particular in env ... Full text Cite

Rate optimal binary linear locally repairable codes with small availability

Conference IEEE International Symposium on Information Theory - Proceedings · August 9, 2017 A locally repairable code with availability has the property that every code symbol can be recovered from multiple, disjoint subsets of other symbols of small size. In particular, a code symbol is said to have (r, t)-availability if it can be recovered fro ... Full text Cite

Multi-scale spectrum sensing in small-cell mm-wave cognitive wireless networks

Conference IEEE International Conference on Communications · July 28, 2017 In this paper, a multi-scale approach to spectrum sensing in cognitive cellular networks is proposed. In order to overcome the huge cost incurred in the acquisition of full network state information, a hierarchical scheme is proposed, based on which local ... Full text Cite

Multi-scale spectrum sensing in millimeter wave cognitive networks

Conference Conference Record of 51st Asilomar Conference on Signals, Systems and Computers, ACSSC 2017 · July 2, 2017 In this paper, a multi-scale approach to spectrum sensing and information exchange in millimeter wave cognitive cellular networks is proposed. In order to overcome the huge energy cost of acquiring full network state information on the occupancy of each ce ... Full text Cite

Run-length limited codes for backscatter communication

Conference ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · June 16, 2017 In backscatter communications, ultra-low power devices signal by modulating the reflection of radio frequency signals emitted from an external source. Unlike conventional one-way communication, the backscatter channel experiences unique self-interference a ... Full text Cite

Information-Theoretic Compressive Measurement Design.

Journal Article IEEE transactions on pattern analysis and machine intelligence · June 2017 An information-theoretic projection design framework is proposed, of interest for feature design and compressive measurements. Both Gaussian and Poisson measurement models are considered. The gradient of a proposed information-theoretic metric (ITM) is der ... Full text Cite

Orthogonal time frequency space modulation

Conference IEEE Wireless Communications and Networking Conference, WCNC · May 10, 2017 A new two-dimensional modulation technique called Orthogonal Time Frequency Space (OTFS) modulation designed in the delay-Doppler domain is introduced. Through this design, which exploits full diversity over time and frequency, OTFS coupled with equalizati ... Full text Cite

Use of a Digital Modified Checklist for Autism in Toddlers - Revised with Follow-up to Improve Quality of Screening for Autism.

Journal Article J Pediatr · April 2017 OBJECTIVES: To assess changes in quality of care for children at risk for autism spectrum disorders (ASD) due to process improvement and implementation of a digital screening form. STUDY DESIGN: The process of screening for ASD was studied in an academic p ... Full text Link to item Cite

Preface

Book · January 1, 2017 Cite

Bounds on the Number of Measurements for Reliable Compressive Classification

Conference IEEE Transactions on Signal Processing · November 15, 2016 This paper studies the classification of high-dimensional Gaussian signals from low-dimensional noisy, linear measurements. In particular, it provides upper bounds (sufficient conditions) on the number of measurements required to drive the probability of m ... Full text Cite

Classification and Reconstruction of High-Dimensional Signals from Low-Dimensional Features in the Presence of Side Information

Conference IEEE Transactions on Information Theory · November 1, 2016 This paper offers a characterization of fundamental limits on the classification and reconstruction of high-dimensional signals from low-dimensional features, in the presence of side information. We consider a scenario where a decoder has access both to li ... Full text Cite

Dual-wavelength pump-probe microscopy analysis of melanin composition.

Journal Article Scientific reports · November 2016 Pump-probe microscopy is an emerging technique that provides detailed chemical information of absorbers with sub-micrometer spatial resolution. Recent work has shown that the pump-probe signals from melanin in human skin cancers correlate well with clinica ... Full text Cite

Beyond double transitivity: Capacity-achieving cyclic codes on erasure channels

Conference 2016 IEEE Information Theory Workshop, ITW 2016 · October 21, 2016 Recently, sequences of error-correcting codes with doubly-transitive permutation groups were shown to achieve capacity on erasure channels under symbol-wise maximum a posteriori (MAP) decoding. From this, it follows that Reed-Muller and primitive narrow-se ... Full text Cite

Methuselah flash: Rewriting codes for extra long storage lifetime

Conference Proceedings - 46th Annual IEEE/IFIP International Conference on Dependable Systems and Networks, DSN 2016 · September 29, 2016 Motivated by embedded systems and datacenters that require long-life components, we extend the lifetime of Flash memory using rewriting codes that allow for multiple writes to a page before it needs to be erased. Although researchers have previously explor ... Full text Cite

Two-user erasure interference channels with local delayed CSIT

Journal Article IEEE Transactions on Information Theory · September 1, 2016 We study the capacity region of two-user erasure interference channels with local delayed channel state information at the transmitters. In our model, transmitters have local mismatched outdated knowledge of the channel gains. We propose a transmission str ... Full text Cite

Reed-muller codes achieve capacity on the quantum erasure channel

Conference IEEE International Symposium on Information Theory - Proceedings · August 10, 2016 The quantum erasure channel is the simplest example of a quantum communication channel and its information capacity is known precisely. The subclass of quantum error-correcting codes called stabilizer codes is known to contain capacity-achieving sequences ... Full text Cite

Rate-distortion bounds on Bayes risk in supervised learning

Conference IEEE International Symposium on Information Theory - Proceedings · August 10, 2016 An information-theoretic framework is presented for estimating the number of labeled samples needed to train a classifier in a parametric Bayesian setting. Ideas from rate-distortion theory are used to derive bounds for the average L1 or L∞ distance betwee ... Full text Cite

When does spatial correlation add value to delayed channel state information?

Conference IEEE International Symposium on Information Theory - Proceedings · August 10, 2016 Fast fading wireless networks with delayed knowledge of the channel state information have received significant attention in recent years. An exception is networks where channels are spatially correlated. This paper characterizes the capacity region of two ... Full text Cite

Mismatch in the Classification of Linear Subspaces: Sufficient Conditions for Reliable Classification

Journal Article IEEE Transactions on Signal Processing · June 15, 2016 This paper considers the classification of linear subspaces with mismatched classifiers. In particular, we assume a model where one observes signals in the presence of isotropic Gaussian noise and the distribution of the signals conditioned on a given clas ... Full text Cite

A general framework for reconstruction and classification from compressive measurements with side information

Conference ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · May 18, 2016 We develop a general framework for compressive linear-projection measurements with side information. Side information is an additional signal correlated with the signal of interest. We investigate the impact of side information on classification and signal ... Full text Cite

The Role of Principal Angles in Subspace Classification

Journal Article IEEE Transactions on Signal Processing · April 15, 2016 Subspace models play an important role in a wide range of signal processing tasks, and this paper explores how the pairwise geometry of subspaces influences the probability of misclassification. When the mismatch between the signal and the model is vanishi ... Full text Cite

A geometric perspective on guesswork

Conference 2015 53rd Annual Allerton Conference on Communication, Control, and Computing, Allerton 2015 · April 4, 2016 Guesswork is the position at which a random string drawn from a given probability distribution appears in the list of strings ordered from the most likely to the least likely. We define the tilt operation on probability distributions and show that it param ... Full text Cite

Informational bottlenecks in two-unicast wireless networks with delayed CSIT

Conference 2015 53rd Annual Allerton Conference on Communication, Control, and Computing, Allerton 2015 · April 4, 2016 We study the impact of delayed channel state information at the transmitters (CSIT) in two-unicast wireless networks with a layered topology and arbitrary connectivity. We introduce a technique to obtain outer bounds to the degrees-of-freedom (DoF) region ... Full text Cite

Data Representation Using the Weyl Transform

Journal Article IEEE Transactions on Signal Processing · April 1, 2016 The Weyl transform is introduced as a rich framework for data representation. Transform coefficients are connected to the Walsh-Hadamard transform of multiscale autocorrelations, and different forms of dyadic periodicity in a signal are shown to appear as ... Full text Cite

Can linear minimum storage regenerating codes be universally secure?

Conference Conference Record - Asilomar Conference on Signals, Systems and Computers · February 26, 2016 We study the problem of making a distributed storage system information-theoretically secure against a passive eavesdropper, and aim to characterize coding schemes that are universally secure for up to a given number of eavesdropped nodes. Specifically, we ... Full text Cite

Quantifying Risk for Anxiety Disorders in Preschool Children: A Machine Learning Approach.

Journal Article PLoS One · 2016 Early childhood anxiety disorders are common, impairing, and predictive of anxiety and mood disorders later in childhood. Epidemiological studies over the last decade find that the prevalence of impairing anxiety disorders in preschool children ranges from ... Full text Link to item Cite

Compressive imaging using fast transform coding

Conference Proceedings of SPIE - The International Society for Optical Engineering · January 1, 2016 We propose deterministic sampling strategies for compressive imaging based on Delsarte-Goethals frames. We show that these sampling strategies result in multi-scale measurements which can be related to the 2D Haar wavelet transform. We demonstrate the effe ... Full text Cite

A rate-distortion framework for supervised learning

Conference IEEE International Workshop on Machine Learning for Signal Processing, MLSP · November 10, 2015 An information-theoretic framework is presented for bounding the number of samples needed for supervised learning in a parametric Bayesian setting. This framework is inspired by an analogy with rate-distortion theory, which characterizes tradeoffs in the l ... Full text Cite

Writing without disturb on phase change memories by integrating coding and layout design

Conference ACM International Conference Proceeding Series · October 5, 2015 We integrate coding techniques and layout design to elimi- nate write-disturb in phase change memories (PCMs), while enhancing lifetime and host-visible capacity. We first pro- pose a checkerboard confguration for cell layout to elimi- nate write-disturb w ... Full text Cite

Classification and reconstruction of compressed GMM signals with side information

Conference IEEE International Symposium on Information Theory - Proceedings · September 28, 2015 This paper offers a characterization of performance limits for classification and reconstruction of high-dimensional signals from noisy compressive measurements, in the presence of side information. We assume the signal of interest and the side information ... Full text Cite

Impact of local delayed CSIT on the capacity region of the two-user interference channel

Conference IEEE International Symposium on Information Theory - Proceedings · September 28, 2015 The coherence time of a wireless channel is often smaller than the delay with which channel state information is available at transmitters. In this paper, we aim to find the most important subset of the channel state information that transmitters need to l ... Full text Cite

Mismatch in the classification of linear subspaces: Upper bound to the probability of error

Conference IEEE International Symposium on Information Theory - Proceedings · September 28, 2015 This paper studies the performance associated with the classification of linear subspaces corrupted by noise with a mismatched classifier. In particular, we consider a problem where the classifier observes a noisy signal, the signal distribution conditione ... Full text Cite

Quantifying computational security subject to source constraints, guesswork and inscrutability

Conference IEEE International Symposium on Information Theory - Proceedings · September 28, 2015 Guesswork forms the mathematical framework for quantifying computational security subject to brute-force determination by query. In this paper, we consider guesswork subject to a per-symbol Shannon entropy budget. We introduce inscrutability rate as the as ... Full text Cite

Cyclic LRC codes and their subfield subcodes

Conference IEEE International Symposium on Information Theory - Proceedings · September 28, 2015 We consider linear cyclic codes with the locality property, or locally recoverable codes (LRC codes). A family of LRC codes that generalizes the classical construction of Reed-Solomon codes was constructed in a recent paper by I. Tamo and A. Barg (IEEE Tra ... Full text Cite

Signal recovery and system calibration from multiple compressive poisson measurements

Journal Article SIAM Journal on Imaging Sciences · September 17, 2015 The measurement matrix employed in compressive sensing typically cannot be known precisely a priori and must be estimated via calibration. One may take multiple compressive measurements, from which the measurement matrix and underlying signals may be estim ... Full text Cite

Alignment with intra-class structure can improve classification

Conference ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · August 4, 2015 High dimensional data is modeled using low-rank subspaces, and the probability of misclassification is expressed in terms of the principal angles between subspaces. The form taken by this expression motivates the design of a new feature extraction method t ... Full text Cite

Multi-scale Bayesian reconstruction of compressive X-ray image

Conference ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · August 4, 2015 A novel multi-scale dictionary based Bayesian reconstruction algorithm is proposed for compressive X-ray imaging, which encodes the material's spectrum by Poisson measurements. Inspired by recently developed compressive X-ray imaging systems [1], this work ... Full text Cite

Polynomial-phase signal direction-finding and source-tracking with a single acoustic vector sensor

Conference ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · August 4, 2015 This paper introduces a new ESPRIT-based algorithm to estimate the direction-of-arrival of an arbitrary degree polynomial-phase signal with a single acoustic vector-sensor. The proposed time-invariant ESPRIT algorithm is based on a matrix-pencil pair deriv ... Full text Cite

Collaborative compressive X-ray image reconstruction

Conference ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · August 4, 2015 The Poisson Factor Analysis (PFA) is applied to recover signals from a Poisson compressive sensing system. Motivated by the recently developed compressive X-ray imaging system, Coded Aperture Coherent Scatter Spectral Imaging (CACSSI) [1], we propose a new ... Full text Cite

Conditioning of Random Block Subdictionaries With Applications to Block-Sparse Recovery and Regression

Journal Article IEEE Transactions on Information Theory · July 1, 2015 The linear model, in which a set of observations is assumed to be given by a linear combination of columns of a matrix (often termed a dictionary), has long been the mainstay of the statistics and signal processing literature. One particular challenge for ... Full text Cite

Efficient linear time-varying system identification using chirp waveforms

Conference Conference Record - Asilomar Conference on Signals, Systems and Computers · April 24, 2015 Linear, time-varying (LTV) systems are operators composed of time shifts, frequency shifts, and complex amplitude scalings that act on continuous finite-energy waveforms. This paper builds upon a novel, resource-efficient method previously proposed by the ... Full text Cite

Identification of Linear Time-Varying Systems Through Waveform Diversity

Journal Article IEEE Transactions on Signal Processing · April 15, 2015 Linear, time-varying (LTV) systems composed of time shifts, frequency shifts, and complex amplitude scalings are operators that act on continuous finite-energy waveforms. This paper presents a novel, resource-efficient method for identifying the parametric ... Full text Cite

Discrimination on the Grassmann Manifold: Fundamental Limits of Subspace Classifiers

Journal Article IEEE Transactions on Information Theory · April 1, 2015 We derive fundamental limits on the reliable classification of linear and affine subspaces from noisy, linear features. Drawing an analogy between discrimination among subspaces and communication over vector wireless channels, we define two Shannon-inspire ... Full text Cite

Geometry-aware deep transform

Conference Proceedings of the IEEE International Conference on Computer Vision · February 17, 2015 Many recent efforts have been devoted to designing sophisticated deep learning structures, obtaining revolutionary results on benchmark datasets. The success of these deep learning methods mostly relies on an enormous volume of labeled training samples to ... Full text Cite

Discriminative robust transformation learning

Conference Advances in Neural Information Processing Systems · January 1, 2015 This paper proposes a framework for learning features that are robust to data variation, which is particularly important when only a limited number of training samples are available. The framework makes it possible to tradeoff the discriminative value of l ... Cite

Dynamic spectrum estimation with minimal overhead via multiscale information exchange

Conference 2015 IEEE Global Communications Conference, GLOBECOM 2015 · January 1, 2015 In this paper, a multiscale approach to spectrum sensing in cognitive cellular networks is analyzed. Observing that wireless interference decays with distance, and that estimating the entire spectrum occupancy across the network entails substantial energy ... Full text Cite

A survey of compressed sensing

Conference · January 1, 2015 Compressed sensing was introduced some ten years ago as an effective way of acquiring signals, which possess a sparse or nearly sparse representation in a suitable basis or dictionary. Due to its solid mathematical backgrounds, it quickly attracted the att ... Full text Cite

Compressive classification: Where wireless communications meets machine learning

Conference · January 1, 2015 This chapter introduces Shannon-inspired performance limits associated with the classification of low-dimensional subspaces embedded in a high-dimensional ambient space from compressive and noisy measurements. In particular, it introduces the diversity-dis ... Full text Cite

A scalable app for measuring autism risk behaviors in young children: A technical validity and feasibility study

Journal Article Proceedings of the 5th EAI International Conference on Wireless Mobile Communication and Healthcare · 2015 Link to item Cite

Preface

Book · January 1, 2015 Cite

Reconstruction of signals drawn from a gaussian mixture via noisy compressive measurements

Journal Article IEEE Transactions on Signal Processing · May 1, 2014 This paper determines to within a single measurement the minimum number of measurements required to successfully reconstruct a signal drawn from a Gaussian mixture model in the low-noise regime. The method is to develop upper and lower bounds that are a fu ... Full text Cite

Soft-decoding-based strategies for relay and interference channels: Analysis and achievable rates using LDPC codes

Journal Article IEEE Transactions on Information Theory · January 1, 2014 We provide a rigorous mathematical analysis of two communication strategies: soft decode-and-forward (soft-DF) for relay channels and soft partial interference-cancelation (soft-IC) for interference channels. Both strategies involve soft estimation, which ... Full text Cite

New codes and inner bounds for exact repair in distributed storage systems

Journal Article 2014 48th Annual Conference on Information Sciences and Systems, CISS 2014 · January 1, 2014 We study the exact-repair tradeoff between storage and repair bandwidth in distributed storage systems (DSS). We give new inner bounds for the tradeoff region and provide code constructions that achieve these bounds. © 2014 IEEE. ... Full text Cite

Questionnaire simplification for fast risk analysis of children's mental health

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · January 1, 2014 Early detection and treatment of psychiatric disorders on children has shown significant impact in their subsequent development and quality of life. The assessment of psychopathology in childhood is commonly carried out by performing long comprehensive int ... Full text Cite

Information-theoretic criteria for the design of compressive subspace classifiers

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · January 1, 2014 Using Shannon theory, we derive fundamental, asymptotic limits on the classification of low-dimensional subspaces from compressive measurements. We identify a syntactic equivalence between the classification of subspaces and the communication of codewords ... Full text Cite

Binary cyclic codes that are locally repairable

Journal Article IEEE International Symposium on Information Theory - Proceedings · January 1, 2014 Codes for storage systems aim to minimize the repair locality, which is the number of disks (or nodes) that participate in the repair of a single failed disk. Simultaneously, the code must sustain a high rate, operate on a small finite field to be practica ... Full text Cite

Discrimination on the grassmann manifold: Fundamental limits of subspace classifiers

Journal Article IEEE International Symposium on Information Theory - Proceedings · January 1, 2014 Repurposing tools and intuitions from Shannon theory, we derive fundamental limits on the reliable classification of high-dimensional signals from low-dimensional features. We focus on the classification of linear and affine subspaces and suppose the featu ... Full text Cite

New codes and inner bounds for exact repair in distributed storage systems

Journal Article IEEE International Symposium on Information Theory - Proceedings · January 1, 2014 We study the exact-repair tradeoff between storage and repair bandwidth in distributed storage systems. We give new inner bounds for the tradeoff region and provide code constructions that achieve these bounds. © 2014 IEEE. ... Full text Cite

Nonlinear information-theoretic compressive measurement design

Conference 31st International Conference on Machine Learning, ICML 2014 · January 1, 2014 We investigate design of general nonlinear functions for mapping high-dimensional data into a lower-dimensional (compressive) space. The nonlinear measurements are assumed contaminated by additive Gaussian noise. Depending on the application, we are either ... Cite

Average case analysis of high-dimensional block-sparse recovery and regression for arbitrary designs

Conference Journal of Machine Learning Research · January 1, 2014 This paper studies conditions for high-dimensional inference when the set of observations is given by a linear combination of a small number of groups of columns of a design matrix, termed the "block-sparse" case. In this regard, it first specifies conditi ... Cite

An improved sub-packetization bound for minimum storage regenerating codes

Journal Article IEEE Transactions on Information Theory · January 1, 2014 Distributed storage systems employ codes to provide resilience to failure of multiple storage disks. In particular, an (n, κ) maximum distance separable (MDS) code stores k symbols in n disks such that the overall system is tolerant to a failure of up to n ... Full text Cite

A new sub-packetization bound for minimum storage regenerating codes

Journal Article IEEE International Symposium on Information Theory - Proceedings · December 19, 2013 Codes for distributed storage systems are often designed to sustain failure of multiple storage disks. Specifically, an (n, k) MDS code stores k symbols in n disks such that the overall system is tolerant to a failure of up to n - k disks. However, access ... Full text Cite

Compressive classification

Journal Article IEEE International Symposium on Information Theory - Proceedings · December 19, 2013 This paper presents fundamental limits associated with compressive classification of Gaussian mixture source models. In particular, we offer an asymptotic characterization of the behavior of the (upper bound to the) misclassification probability associated ... Full text Cite

Information-theoretic limits on the classification of Gaussian mixtures: Classification on the Grassmann manifold

Journal Article 2013 IEEE Information Theory Workshop, ITW 2013 · December 1, 2013 Motivated by applications in high-dimensional signal processing, we derive fundamental limits on the performance of compressive linear classifiers. By analogy with Shannon theory, we define the classification capacity, which quantifies the maximum number o ... Full text Cite

Projections designs for compressive classification

Journal Article 2013 IEEE Global Conference on Signal and Information Processing, GlobalSIP 2013 - Proceedings · December 1, 2013 This paper puts forth projections designs for compressive classification of Gaussian mixture models. In particular, we capitalize on the asymptotic characterization of the behavior of an (upper bound to the) misclassification probability associated with th ... Full text Cite

Reconstruction of Gaussian mixture models from compressive measurements: A phase transition view

Journal Article 2013 IEEE Global Conference on Signal and Information Processing, GlobalSIP 2013 - Proceedings · December 1, 2013 We characterize the minimum number of measurements needed to drive to zero the minimum mean squared error (MMSE) of Gaussian mixture model (GMM) input signals in the low-noise regime. The result also hints at almost phase-transition optimal recovery proced ... Full text Cite

Low-rank matrix recovery with poison noise

Journal Article 2013 IEEE Global Conference on Signal and Information Processing, GlobalSIP 2013 - Proceedings · December 1, 2013 Estimating an image M* +m1×m2 from its linear measurements under Poisson noise is an important problem arises from applications such as optical imaging, nuclear medicine and x-ray imaging [1]. When the image M* has a low-rank structure, we can use a small ... Full text Cite

PETRELS: Parallel subspace estimation and tracking by recursive least squares from partial observations

Journal Article IEEE Transactions on Signal Processing · November 27, 2013 Many real world datasets exhibit an embedding of low-dimensional structure in a high-dimensional manifold. Examples include images, videos and internet traffic data. It is of great significance to estimate and track the low-dimensional structure with small ... Full text Cite

Knowledge-enhanced matching pursuit

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · October 18, 2013 Compressive Sensing is possible when the sensing matrix acts as a near isometry on signals of interest that can be sparsely or compressively represented. The attraction of greedy algorithms such as Orthogonal Matching Pursuit is their simplicity. However t ... Full text Cite

Compressed sensing with corrupted participants

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · October 18, 2013 Compressed sensing (CS) theory promises one can recover real-valued sparse signal from a small number of linear measurements. Motivated by network monitoring with link failures, we for the first time consider the problem of recovering signals that contain ... Full text Cite

Compressive sensing for incoherent imaging systems with optical constraints

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · October 18, 2013 We consider the problem of linear projection design for incoherent optical imaging systems. We propose a computationally efficient method to obtain effective measurement kernels that satisfy the physical constraints imposed by an optical system, starting f ... Full text Cite

Data secrecy in distributed storage systems under exact repair

Journal Article 2013 International Symposium on Network Coding, NetCod 2013 · September 9, 2013 The problem of securing data against eavesdropping in distributed storage systems is studied. The focus is on systems that use linear codes and implement exact repair to recover from node failures. The maximum file size that can be stored securely is deter ... Full text Cite

On block coherence of frames

Journal Article · July 29, 2013 Block coherence of matrices plays an important role in analyzing the performance of block compressed sensing recovery algorithms (Bajwa and Mixon, 2012). In this paper, we characterize two block coherence metrics: worst-case and average block coherence. Fi ... Link to item Cite

Coset coding to extend the lifetime of memory

Journal Article Proceedings - International Symposium on High-Performance Computer Architecture · July 23, 2013 Some recent memory technologies, including phase change memory (PCM), have lifetime reliabilities that are affected by write operations. We propose the use of coset coding to extend the lifetimes of these memories. The key idea of coset coding is that it p ... Full text Cite

Performance of the Delsarte-Goethals frame on clustered sparse vectors

Journal Article IEEE Transactions on Signal Processing · April 5, 2013 The Delsarte-Goethals frame (DGF) has been proposed for deterministic compressive sensing of sparse and compressible signals. Results in compressive sensing theory show that the DGF enables successful recovery of an overwhelming majority of sufficiently sp ... Full text Cite

A constrained random demodulator for sub-nyquist sampling

Journal Article IEEE Transactions on Signal Processing · February 1, 2013 This paper presents a significant modification to the Random Demodulator (RD) of Tropp et al. for sub-Nyquist sampling of frequency-sparse signals. The modification, termed constrained random demodulator, involves replacing the random waveform, essential t ... Full text Cite

Painting analysis using wavelets and probabilistic topic models

Journal Article 2013 IEEE International Conference on Image Processing, ICIP 2013 - Proceedings · January 1, 2013 In this paper, computer-based techniques for stylistic analysis of paintings are applied to the five panels of the 14th century Peruzzi Altarpiece by Giotto di Bondone. Features are extracted by combining a dual-tree complex wavelet transform with a hidden ... Full text Cite

Designed measurements for vector count data

Journal Article Advances in neural information processing systems · 2013 Cite

Toward resource-optimal consensus over the wireless medium

Journal Article IEEE Journal on Selected Topics in Signal Processing · January 1, 2013 We carry out a comprehensive study of the resource cost of averaging consensus in wireless networks. Most previous approaches suppose a graphical network, which abstracts away crucial features of the wireless medium, and measure resource consumption only i ... Full text Cite

Shaping the Power Spectra of Bipolar Sequences with Application to Sub-Nyquist Sampling

Conference 2013 IEEE 5TH INTERNATIONAL WORKSHOP ON COMPUTATIONAL ADVANCES IN MULTI-SENSOR ADAPTIVE PROCESSING (CAMSAP 2013) · January 1, 2013 Link to item Cite

Resource-Efficient Parametric Recovery of Linear Time-Varying Systems

Conference 2013 IEEE 5TH INTERNATIONAL WORKSHOP ON COMPUTATIONAL ADVANCES IN MULTI-SENSOR ADAPTIVE PROCESSING (CAMSAP 2013) · January 1, 2013 Link to item Cite

Coherence-based performance guarantees of Orthogonal Matching Pursuit

Journal Article 2012 50th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2012 · December 1, 2012 In this paper, we present coherence-based performance guarantees of Orthogonal Matching Pursuit (OMP) for both support recovery and signal reconstruction of sparse signals when the measurements are corrupted by noise. In particular, two variants of OMP eit ... Full text Cite

Toward resource-optimal averaging consensus over the wireless medium

Journal Article Conference Record - Asilomar Conference on Signals, Systems and Computers · December 1, 2012 We carry out a comprehensive study of the resource costs of distributed averaging consensus in wireless sensor networks. In particular, we consider two metrics appropriate to the wireless medium: total transmit energy and time-bandwidth product. Most previ ... Full text Cite

Writing cosets of a convolutional code to increase the Lifetime of Flash memory

Journal Article 2012 50th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2012 · December 1, 2012 The goal of this paper is to extend the lifetime of Flash memory by reducing the frequency with which a given page of memory is erased. This is accomplished by increasing the number of writes that are possible before erasure is necessary. Redundancy is int ... Full text Cite

Rapid sensing of underutilized, wideband spectrum using the Random Demodulator

Journal Article Conference Record - Asilomar Conference on Signals, Systems and Computers · December 1, 2012 Efficient spectrum sensing is an important problem given the large and increasing demand for wireless spectrum and the need to protect incumbent users. We can more efficiently use large swaths of underutilized spectrum by designing spectrum sensors that ca ... Full text Cite

Enabling code diversity for mobile radio channels using long-range fading prediction

Journal Article IEEE Transactions on Wireless Communications · November 29, 2012 Code diversity integrates space-time coding with beamforming by using a small number of feedback bits to select from a family of space-time codes. Different codes lead to different induced channels at the receiver, where Channel State Information (CSI) is ... Full text Cite

Compressive demodulation of mutually interfering signals

Journal Article 2012 IEEE Statistical Signal Processing Workshop, SSP 2012 · November 6, 2012 The challenge of Multiuser Detection (MUD) is that of demodulating mutually interfering signals given that at any time instant the number of active users is typically small. The promise of compressed sensing is the demodulation of sparse superpositions of ... Full text Cite

Melanoma classification from hidden Markov tree features

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · October 23, 2012 Melanoma detection relies on visual inspection of skin samples under the microscope via a qualitative set of indicators, causing large discordance among pathologists. New developments in pump-probe imaging enable the extraction of melanin intensity levels ... Full text Cite

Finding needles in compressed haystacks

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · October 23, 2012 In this paper, we investigate the problem of compressed learning, i.e. learning directly in the compressed domain. In particular, we provide tight bounds demonstrating that the linear kernel SVMs classifier in the measurement domain, with high probability, ... Full text Cite

Hierarchical averaging over wireless sensor networks

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · October 23, 2012 We introduce an approach to gossip algorithms that exploits three aspects of the wireless medium: superposition, broadcast, and power control. Instead of sending pairwise messages between neighbors on a fixed network topology, we construct gossip algorithm ... Full text Cite

How to focus the discriminative power of a dictionary

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · October 23, 2012 This paper is motivated by the challenge of high fidelity processing of images using a relatively small set of projection measurements. This is a problem of great interest in many sensing applications, for example where high photodetector counts are preclu ... Full text Cite

A novel approach to Doppler compensation and estimation for multiple targets in MIMO radar with unitary waveform matrix scheduling

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · October 23, 2012 In this paper, we present a method of detecting the range and Doppler phase of a point target using multiple antennas. As a key illustrative example, we consider a 4 x 4 system employing a unitary matrix waveform set, e.g., formed from Golay complementary ... Full text Cite

PETRELS: Subspace estimation and tracking from partial observations

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · October 23, 2012 We consider the problem of reconstructing a data stream from a small subset of its entries, where the data stream is assumed to lie in a low-dimensional linear subspace, possibly corrupted by noise. It is also important to track the change of underlying su ... Full text Cite

Beyond worst-case reconstruction in deterministic compressed sensing

Journal Article IEEE International Symposium on Information Theory - Proceedings · October 22, 2012 The role of random measurement in compressive sensing is analogous to the role of random codes in coding theory. In coding theory, decoders that can correct beyond the minimum distance of a code allow random codes to achieve the Shannon limit. In compresse ... Full text Cite

Communications inspired linear discriminant analysis

Journal Article Proceedings of the 29th International Conference on Machine Learning, ICML 2012 · October 10, 2012 We study the problem of supervised linear dimensionality reduction, taking an information-theoretic viewpoint. The linear projection matrix is designed by maximizing the mutual information between the projected signal and the class label. By harnessing a r ... Open Access Cite

Two are better than one: Fundamental parameters of frame coherence

Journal Article Applied and Computational Harmonic Analysis · July 1, 2012 This paper investigates two parameters that measure the coherence of a frame: worst-case and average coherence. We first use worst-case and average coherence to derive near-optimal probabilistic guarantees on both sparse signal detection and reconstruction ... Full text Cite

Asynchronous code-division random access using convex optimization

Journal Article Physical Communication · June 1, 2012 Many applications in cellular systems and sensor networks involve a random subset of a large number of users asynchronously reporting activity to a base station. This paper examines the problem of multiuser detection (MUD) in random access channels for suc ... Full text Cite

On design of rateless codes over dying binary erasure channel

Journal Article IEEE Transactions on Communications · April 1, 2012 In this paper, we study a practical coding scheme for the dying binary erasure channel (DBEC), which is a binary erasure channel (BEC) subject to a random fatal failure. We consider the rateless codes and optimize the degree distribution to maximize the av ... Full text Cite

Communications-inspired projection design with application to compressive sensing

Journal Article SIAM Journal on Imaging Sciences · January 1, 2012 We consider the recovery of an underlying signal x ∈ ℂm based on projection measurements of the form y = Mx+w, where y ∈ ℂℓ and w is measurement noise; we are interested in the case ℓ ≪ m. It is assumed that the signal model p(x) is known and that w ~ CN(w ... Full text Open Access Cite

On training signal design for multi-user MIMO-OFDM: Performance analysis and tradeoffs

Journal Article IEEE Vehicular Technology Conference · December 23, 2011 This paper addresses spectrally-efficient multiantenna multi-carrier uplink transmission scenarios where the users overlap in time and frequency and are separated using spatial processing at the base station. The robustness of the proposed training sequenc ... Full text Cite

Covering radius and the Restricted Isometry Property

Journal Article 2011 IEEE Information Theory Workshop, ITW 2011 · December 21, 2011 The Restricted Isometry Property or RIP introduced by Candes and Tao requires an n × p dictionary to act as a near isometry on all k-sparse signals. This paper provides a very simple condition under which a dictionary Φ (C) obtained by exponentiating codew ... Full text Cite

Imaging the distribution of melanin in human skin lesions with pump-probe microscopy

Journal Article Optics InfoBase Conference Papers · December 1, 2011 Cite

MMSE-optimal training sequences for spectrally-efficient Multi-User MIMO-OFDM systems

Journal Article European Signal Processing Conference · December 1, 2011 This paper proposes a new family of optimal training sequences in terms of minimizing the mean-square channel estimation error for spectrally-efficient Multi-User MIMO-OFDM systems with an arbitrary number of transmit antennas and an arbitrary number of tr ... Cite

Capacity optimization in networks with heterogeneous radio access technologies

Journal Article GLOBECOM - IEEE Global Telecommunications Conference · December 1, 2011 As it becomes common for wireless service providers (WSP) to employ multiple heterogeneous radio access technologies (RAT), the management of the combined resources across multiple RATs arises as an important issue. The WSP's objective is to assign differe ... Full text Cite

Coordinating complementary waveforms for sidelobe suppression

Journal Article Conference Record - Asilomar Conference on Signals, Systems and Computers · December 1, 2011 We present a general method for constructing radar transmit pulse trains and receive filters for which the radar point-spread function in delay and Doppler, given by the cross-ambiguity function of the transmit pulse train and the pulse train used in the r ... Full text Cite

Gossiping in groups: Distributed averaging over the wireless medium

Journal Article 2011 49th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2011 · December 1, 2011 We present an approach to gossip algorithms tailored to the practical considerations of wireless communications. Traditional gossip algorithms operate via the pairwise exchange of estimates, which fails to capture the broadcast and superposition nature of ... Full text Cite

Choir codes: Coding for full duplex interference management

Journal Article 2011 49th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2011 · December 1, 2011 Communication networks conventionally operate with half-duplex methods and interference avoiding schemes to manage multiple transceivers. Here we consider a method in which nodes transmit and receive in concert to achieve full duplex communication without ... Full text Cite

Frame coherence and sparse signal processing

Journal Article IEEE International Symposium on Information Theory - Proceedings · October 26, 2011 The sparse signal processing literature often uses random sensing matrices to obtain performance guarantees. Unfortunately, in the real world, sensing matrices do not always come from random processes. It is therefore desirable to evaluate whether an arbit ... Full text Cite

Deterministic pilot sequences for sparse channel estimation in OFDM systems

Journal Article 17th DSP 2011 International Conference on Digital Signal Processing, Proceedings · September 29, 2011 This paper examines the problem of multipath channel estimation in single-antenna orthogonal frequency division multiplexing (OFDM) systems. In particular, we study the problem of pilot assisted channel estimation in wideband OFDM systems, where the time-d ... Full text Cite

Fast level set estimation from projection measurements

Journal Article IEEE Workshop on Statistical Signal Processing Proceedings · September 5, 2011 Estimation of the level set of a function (i.e., regions where the function exceeds some value) is an important problem with applications in digital elevation maps, medical imaging, and astronomy. In many applications, however, the function of interest is ... Full text Cite

Performance bounds for expander-based compressed sensing in poisson noise

Journal Article IEEE Transactions on Signal Processing · September 1, 2011 This paper provides performance bounds for compressed sensing in the presence of Poisson noise using expander graphs. The Poisson noise model is appropriate for a variety of applications, including low-light imaging and digital streaming, where the signal- ... Full text Cite

The effect of eavesdroppers on network connectivity: A secrecy graph approach

Journal Article IEEE Transactions on Information Forensics and Security · September 1, 2011 This paper investigates the effect of eavesdroppers on network connectivity, using a wiretap model and percolation theory. The wiretap model captures the effect of eavesdroppers on link security. A link exists between two nodes only if the secrecy capacity ... Full text Cite

Beating Nyquist through correlations: A constrained random demodulator for sampling of sparse bandlimited signals

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · August 18, 2011 Technological constraints severely limit the rate at which analog-to-digital converters can reliably sample signals. Recently, Tropp et al. proposed an architecture, termed the random demodulator (RD), that attempts to overcome this obstacle for sparse ban ... Full text Cite

The value of redundant measurement in compressed sensing

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · August 18, 2011 The aim of compressed sensing is to recover attributes of sparse signals using very few measurements. Given an overall bit budget for quantization, this paper demonstrates that there is value to redundant measurement. The measurement matrices considered he ... Full text Cite

On optimal precoding in wireless multicast systems

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · August 18, 2011 Precoding has been extensively studied for point-to-point communications, including the problems of constructing the precoding codebook and selecting the best precoder. This paper investigates precoding for a multicast channel in which a base station is se ... Full text Cite

When to add another dimension when communicating over MIMO channels

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · August 18, 2011 This paper introduces a divide and conquer approach to the design of transmit and receive filters for communication over a Multiple Input Multiple Output (MIMO) Gaussian channel subject to an average power constraint. It involves conversion to a set of par ... Full text Cite

Uncovering elements of style

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · August 18, 2011 This paper relates the style of 16th century Flemish paintings by Goossen van der Weyden (GvdW) to the style of preliminary sketches or underpaintings made prior to executing the painting. Van der Weyden made underpaintings in markedly different styles for ... Full text Cite

Training signal design and tradeoffs for spectrally-efficient multi-user MIMO-OFDM systems

Journal Article IEEE Transactions on Wireless Communications · July 1, 2011 In this paper, we design MMSE-optimal training sequences for multi-user MIMO-OFDM systems with an arbitrary number of transmit antennas and an arbitrary number of training symbols. It addresses spectrally-efficient uplink transmission scenarios where the u ... Full text Cite

Sparse fusion frames: Existence and construction

Journal Article Advances in Computational Mathematics · July 1, 2011 Fusion frame theory is an emerging mathematical theory that provides a natural framework for performing hierarchical data processing. A fusion frame can be regarded as a frame-like collection of subspaces in a Hilbert space, and thereby generalizes the con ... Full text Cite

Fast essentially maximum likelihood decoding of the Golden code

Journal Article IEEE Transactions on Information Theory · June 1, 2011 The Golden code is a full-rate full-diversity space-time code which has been incorporated in the IEEE 802.16 (WiMAX) standard. The worst case complexity of a tree-based sphere decoder for a square QAM constellation is O(N 3), where n is the size of the und ... Full text Cite

Layered coding for interference channels with partial transmitter side information

Journal Article IEEE Transactions on Information Theory · May 1, 2011 A two-user interference channel is considered where each transmitter has access to a part of the information intended to the other destination. A primary objective is to maximize the information rates, by exploring the cooperation between the transmitters ... Full text Cite

Sensitivity to basis mismatch in compressed sensing

Journal Article IEEE Transactions on Signal Processing · May 1, 2011 The theory of compressed sensing suggests that successful inversion of an image of the physical world (broadly defined to include speech signals, radar/sonar returns, vibration records, sensor array snapshot vectors, 2-D images, and so on) for its source m ... Full text Cite

Congestion control and its stability in networks with delay sensitive traffic

Journal Article Computer Networks · January 7, 2011 We consider congestion control in a network with delay sensitive/ insensitive traffic, modelled by adding explicit delay terms to the utility function measuring user's happiness on the Quality of Service (QoS). A new Network Utility Maximization (NUM) prob ... Full text Cite

Imaging the distribution of melanin in human skin lesions with pump-probe microscopy

Conference Optics InfoBase Conference Papers · January 1, 2011 Full text Cite

Unitary design of radar waveform diversity sets

Journal Article Digital Signal Processing: A Review Journal · January 1, 2011 In this work, multiple radar waveforms are simultaneously transmitted, emitted from different antennas. The goal is to process the returns in such a way that the overall ambiguity function is a sum of individual ambiguity functions, such that the sum bette ... Full text Cite

Detecting weak but hierarchically-structured patterns in networks

Journal Article Journal of Machine Learning Research · December 1, 2010 The ability to detect weak distributed activation patterns in networks is critical to several applications, such as identifying the onset of anomalous activity or incipient congestion in the Internet, or faint traces of a biochemical spread by a sensor net ... Cite

The projective Kerdock code

Journal Article 2010 IEEE Information Theory Workshop, ITW 2010 - Proceedings · December 1, 2010 Certain nonlinear binary codes can be constructed as binary images of Z4-linear codes under the Gray map. Examples include the second-order Reed-Muller code and the Kerdock and Preparata codes. In this paper, we consider a new quaternary code which is an a ... Full text Cite

Space-time processing for MIMO-OFDM using DFT-based complementary sequences

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · December 1, 2010 In this paper, a new space-time signaling scheme is proposed for Orthogonal Frequency Division Multiplexing (OFDM) using complementary sequences derived from the rows of the DFT matrix. The autocorrelative properties of the complementary sequences allows m ... Full text Cite

Multiuser detection in asynchronous on-off random access channels using lasso

Journal Article 2010 48th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2010 · December 1, 2010 This paper considers on-off random access channels where users transmit either a one or a zero to a base station. Such channels represent an abstraction of control channels used for scheduling requests in third-generation cellular systems and uplinks in wi ... Full text Cite

Revisiting model selection and recovery of sparse signals using one-step thresholding

Journal Article 2010 48th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2010 · December 1, 2010 This paper studies non-asymptotic model selection and recovery of sparse signals in high-dimensional, linear inference problems. In contrast to the existing literature, the focus here is on the general case of arbitrary design matrices and arbitrary nonzer ... Full text Cite

Compressive blind source separation

Journal Article Proceedings - International Conference on Image Processing, ICIP · December 1, 2010 The central goal of compressive sensing is to reconstruct a signal that is sparse or compressible in some basis using very few measurements. However reconstruction is often not the ultimate goal and it is of considerable interest to be able to deduce attri ... Full text Cite

Reed Muller sensing matrices and the LASSO (Invited paper)

Journal Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) · November 19, 2010 We construct two families of deterministic sensing matrices where the columns are obtained by exponentiating codewords in the quaternary Delsarte-Goethals code DG(m,r). This method of construction results in sensing matrices with low coherence and spectral ... Full text Cite

Grassmannian packings from operator ReedMuller codes

Journal Article IEEE Transactions on Information Theory · November 1, 2010 This paper introduces multidimensional generalizations of binary Reed-Muller codes where the codewords are projection operators, and the corresponding subspaces are widely separated with respect to the chordal distance on Grassmannian space. Parameters of ... Full text Cite

Pricing broadband: Survey and open problems

Journal Article ICUFN 2010 - 2nd International Conference on Ubiquitous and Future Networks · October 4, 2010 Driven by the emerging directions from the FCC and the broadband market, this paper aims at answering the fundamental question of how to use pricing as a lever to enable universal broadband coverage and effective network management in the United States. We ... Full text Cite

Volume thresholds for quantum fault tolerance

Journal Article Quantum Information Processing · October 1, 2010 We introduce finite-level concatenation threshold regions for quantum fault tolerance. These volume thresholds are regions in an error probability manifold that allow for the implemented system dynamics to satisfy a prescribed implementation inaccuracy bou ... Full text Cite

Sparse reconstruction via the reed-muller sieve

Journal Article IEEE International Symposium on Information Theory - Proceedings · August 23, 2010 This paper introduces the Reed Muller Sieve, a deterministic measurement matrix for compressed sensing. The columns of this matrix are obtained by exponentiating codewords in the quaternary second order Reed Muller code of length N. For k = O(N), the Reed ... Full text Cite

Modeling location uncertainty for eavesdroppers: A secrecy graph approach

Journal Article IEEE International Symposium on Information Theory - Proceedings · August 23, 2010 In this paper, we consider end-to-end secure communication in a large wireless network, where the locations of eavesdroppers are uncertain. Our framework attempts to bridge the gap between physical layer security under uncertain channel state information o ... Full text Cite

Model selection: Two fundamental measures of coherence and their algorithmic significance

Journal Article IEEE International Symposium on Information Theory - Proceedings · August 23, 2010 The problem of model selection arises in a number of contexts, such as compressed sensing, subset selection in linear regression, estimation of structures in graphical models, and signal denoising. This paper generalizes the notion of incoherence in the ex ... Full text Cite

Regularized blind detection for MIMO communications

Journal Article IEEE International Symposium on Information Theory - Proceedings · August 23, 2010 Multiple-Input Multiple-Output (MIMO) systems improve the throughput and reliability of wireless communications. Perfect Channel State Information (CSI) is needed at the receiver to perform coherent detection and achieve the optimal gain of the system. In ... Full text Cite

The Value of Staying Current when Beamforming

Journal Article · July 29, 2010 Beamforming is a widely used method of provisioning high quality wireless channels that leads to high data rates and simple decoding structures. It requires feedback of Channel State Information (CSI) from receiver to transmitter, and the accuracy of this ... Link to item Cite

Fishing in poisson streams: Focusing on the whales, ignoring the minnows

Journal Article 2010 44th Annual Conference on Information Sciences and Systems, CISS 2010 · June 24, 2010 This paper describes a low-complexity approach for reconstructing average packet arrival rates and instantaneous packet counts at a router in a communication network, where the arrivals of packets in each flow follow a Poisson process. Assuming that the ra ... Full text Cite

Pricing under constraints in access networks: Revenue maximization and congestion management

Journal Article Proceedings - IEEE INFOCOM · June 15, 2010 This paper investigates pricing of Internet connectivity services in the context of a monopoly ISP selling broadband access to consumers. We first study the optimal combination of flat-rate and usage-based access price components for maximization of ISP re ... Full text Cite

Network resource allocation for competing multiple description transmissions

Journal Article IEEE Transactions on Communications · May 1, 2010 Providing real-time multimedia services over a besteffort network is challenging due to the stringent delay requirements in the presence of complex network dynamics. Multiple description (MD) coding is one approach to transmit the media over diverse (multi ... Full text Cite

Construction of a large class of deterministic sensing matrices that satisfy a statistical isometry property

Journal Article IEEE Journal on Selected Topics in Signal Processing · April 1, 2010 Compressed Sensing aims to capture attributes of κ-sparse signals using very few measurements. In the standard compressed sensing paradigm, the N × C measurement matrix Φ is required to act as a near isometry on the set of all κ-sparse signals (restricted ... Full text Cite

Intelligent video network engineering with distributed optimization: Two case studies

Journal Article Studies in Computational Intelligence · March 24, 2010 Video is becoming the dominant traffic over the Internet. To provide better Quality of Service (QoS) to the end users, while also achieve network resource efficiency, is an important problem for both network operators, content providers and consumers. In t ... Full text Cite

Fast optimal decoding of multiplexed orthogonal designs by conditional optimization

Journal Article IEEE Transactions on Information Theory · March 1, 2010 This paper focuses on conditional optimization as a decoding primitive for high rate spacetime codes that are obtained by multiplexing in the spatial and code domains. The approach is a crystallization of the work of Hottinen which applies to spacetime cod ... Full text Cite

Why Gabor frames? Two fundamental measures of coherence and their role in model selection

Journal Article Journal of Communications and Networks · January 1, 2010 The problem of model selection arises in a number of contexts, such as subset selection in linear regression, estimation of structures in graphical models, and signal denoising. This paper studies non-asymptotic model selection for the general case of arbi ... Full text Cite

On the effect of feedback delay on limited-rate beamforming systems

Journal Article GLOBECOM - IEEE Global Telecommunications Conference · January 1, 2010 The use of beamforming to enable higher data rates in telecommunications is widely appreciated, but performance gains are typically calculated assuming delay-free feedback from the receiver and neglecting processing time. This paper introduces a mathematic ... Full text Cite

Circulant space-time codes for integration with beamforming

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · January 1, 2010 This paper provides a framework for designing space-time codes to take advantage of a small number of feedback bits from the receiver. The new codes are based on circulant matrices and simple conditions are derived that guarantee full rate and full diversi ... Full text Cite

Target detection in mimo radar in the presence of doppler using complementary sequences

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · January 1, 2010 In this paper, we present a method for detecting a point target using multiple antennas when the relative motion between the receivers and the target induces a non-negligible Doppler shift. As a key illustrative example, we consider a 4x4 system employing ... Full text Cite

Sensitivity to basis mismatch in compressed sensing

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · January 1, 2010 Compressed sensing theory suggests that successful inversion of an image of the physical world from its modal parameters can be achieved at measurement dimensions far lower than the image dimension, provided that the image is sparse in an a priori known ba ... Full text Cite

Reed Muller Sensing Matrices and the LASSO

Journal Article SEQUENCES AND THEIR APPLICATIONS-SETA 2010 · 2010 Cite

Ergodic layered erasure one-sided interference channels

Journal Article 2009 IEEE Information Theory Workshop, ITW 2009 · December 7, 2009 The sum capacity of a class of layered erasure onesided interference channels is developed under the assumption of no channel state information at the transmitters. Outer bounds are presented for this model and are shown to be tight for the following sub-c ... Full text Cite

Introduction to the issue on managing complexity in multiuser MIMO systems

Journal Article IEEE Journal on Selected Topics in Signal Processing · December 1, 2009 Full text Cite

Finite precision analysis for space-time decoding

Journal Article IEEE Transactions on Signal Processing · December 1, 2009 Low complexity optimal (or nearly optimal) decoders for space-time codes have recently been under intensive investigation. For example, recent works by Sirianunpiboon and others show that the Silver code and the Golden code can be decoded optimally (or nea ... Full text Cite

Spatio-temporal scheduling of complementary sequences with application to MIMO-OFDM

Journal Article Conference Record - Asilomar Conference on Signals, Systems and Computers · December 1, 2009 In this paper, a new method of space-time processing is proposed for Orthogonal Frequency Division Multiplexing (OFDM) using complementary sequences derived from the rows of the DFT matrix. The autocorrelative properties of the complementary sequences allo ... Full text Cite

Target detection in MIMO radar using golay complementary sequences in the presence of doppler

Journal Article Conference Record - Asilomar Conference on Signals, Systems and Computers · December 1, 2009 In this paper, we present a method for detecting a point target using multiple antennas when the relative motion between the receivers and the target induces a non-trivial Doppler shift. We consider a 4×4 system employing sets of unitary waveforms. In case ... Full text Cite

A scheme for fully polarimetric MIMO multiuser detection

Journal Article Conference Record - Asilomar Conference on Signals, Systems and Computers · December 1, 2009 Multiple-Input Multiple-Output (MIMO) functionality has been shown to dramatically increase the capacity of wireless communication systems when the environment provides rich multipath scattering. In a predominantly Line-of-Sight (LOS) environment, the loss ... Full text Cite

Performance bounds for expander-based compressed sensing in the presence of Poisson noise

Journal Article Conference Record - Asilomar Conference on Signals, Systems and Computers · December 1, 2009 This paper provides performance bounds for compressed sensing in the presence of Poisson noise using expander graphs. The Poisson noise model is appropriate for a variety of applications, including low-light imaging and digital streaming, where the signal- ... Full text Cite

Fully-polarimetric MIMO to improve throughput and reliability across propagation conditions

Journal Article IEEE Vehicular Technology Conference · December 1, 2009 Multiple-Input Multiple-Output (MIMO) functionality has been shown to dramatically increase the capacity of wireless communication systems when the environment provides rich multipath scattering. In a predominantly Line-of-Sight (LOS) environment, the loss ... Full text Cite

Golay complementary waveforms for sparse delay-Doppler radar imaging

Journal Article CAMSAP 2009 - 2009 3rd IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing · December 1, 2009 We present a new approach to radar imaging that exploits sparsity in the matched filter domain to enable high resolution imaging of targets in delay and Doppler. We show that the vector of radar cross-ambiguity values at any fixed test delay cell has a spa ... Full text Cite

Highly parallel decoding of space-time codes on graphics processing units

Journal Article 2009 47th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2009 · December 1, 2009 Graphics Processing Units (GPUs) with a few hundred extremely simple processors represent a paradigm shift for highly parallel computations. We use this emergent GPU architecture to provide a first demonstration of the feasibility of real time ML decoding ... Full text Cite

A sublinear algorithm for sparse reconstruction with ℓ2/ ℓ2 recovery guarantees

Journal Article CAMSAP 2009 - 2009 3rd IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing · December 1, 2009 Compressed Sensing aims to capture attributes of a sparse signal using very few measurements. Candès and Tao showed that sparse reconstruction is possible if the sensing matrix acts as a near isometry on all k-sparse signals. This property holds with overw ... Full text Cite

Target detection in MIMO radar using Golay complementary sequences in the presence of doppler

Journal Article 2009 47th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2009 · December 1, 2009 In this paper, we present a method for detecting a point target using multiple antennas when the relative motion between the receivers and the target induces a non-negligible Doppler shift. As a key illustrative example, we consider a 4 x 4 system employin ... Full text Cite

Enhanced CDMA communications using compressed-sensing reconstruction methods

Journal Article 2009 47th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2009 · December 1, 2009 We propose a simple method for downlink communications based on second order Reed-Muller sequences which generalize the Walsh sequences that are used in orthogonal CDMA. In our approach, coding occurs at the chip level (i.e. we use a spreading factor of 1) ... Full text Cite

Integration of code diversity and long-range channel prediction in wireless communication

Journal Article Proceedings of the 2009 International Conference on Electromagnetics in Advanced Applications, ICEAA '09 · December 1, 2009 Code diversity integrates space-time coding with beamforming by using a small number of feedback bits to select from a family of space-time codes. Different codes lead to different induced channels at the receiver, where Channel State information (CSI) is ... Full text Cite

Engineering fault tolerance for realistic quantum systems via the full error dynamics of quantum codes

Journal Article IEEE International Symposium on Information Theory - Proceedings · November 19, 2009 The standard approach to quantum fault tolerance is to calculate error thresholds on basic gates in the limit of arbitrarily many concatenation levels. In contrast this paper takes the number of qubits and the target implementation accuracy as given, and p ... Full text Cite

Construction of high rate super-orthogonal space-time block codes

Journal Article IEEE International Conference on Communications · November 19, 2009 It is standard practice to integrate outer trellis codes with inner space-time block codes to increase coding gain, but the drawback is a decrease in rate. Jafarkhani and Seshadri [1] have introduced an alternative method of combining multiple inner orthog ... Full text Cite

Information secrecy from multiple eavesdroppers in orthogonal relay channels

Journal Article IEEE International Symposium on Information Theory - Proceedings · November 19, 2009 The secrecy capacity of relay channels with orthogonal components is studied in the presence of additional passive eavesdropper nodes. The relay and destination receive signals from the source on two orthogonal channels such that the destination also recei ... Full text Cite

Constructing fusion frames with desired parameters

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · November 19, 2009 A fusion frame is a frame-like collection of subspaces in a Hilbert space. It generalizes the concept of a frame system for signal representation. In this paper, we study the existence and construction of fusion frames. We first introduce two general metho ... Full text Cite

Wiretap channel type II with an active eavesdropper

Journal Article IEEE International Symposium on Information Theory - Proceedings · November 19, 2009 The wiretap channel type II with an active eavesdropper is considered in this paper. Compared with the eavesdropper model considered in much of the literature, the eavesdropper considered here can not only overhear but also modify the signal transmitted ov ... Full text Cite

On the capacity of the discrete-time channel with uniform output quantization

Journal Article IEEE International Symposium on Information Theory - Proceedings · November 19, 2009 This paper provides new insight into the classical problem of determining both the capacity of the discrete-time channel with uniform output quantization and the capacity achieving input distribution. It builds on earlier work by Gallager and Witsenhausen ... Full text Cite

Network pricing and rate allocation with content provider participation

Journal Article Proceedings - IEEE INFOCOM · October 12, 2009 Pricing content-providers for connectivity to endusers and setting connection parameters based on the price is an evolving model on the Internet. The implications are heavily debated in telecom policy circles, and some advocates of "Network Neutrality" hav ... Full text Cite

Secrecy capacity of a class of orthogonal relay eavesdropper channels

Journal Article Information Theory and Applications Workshop, ITA 2009 · September 25, 2009 The secrecy capacity is developed for a class of relay channels with orthogonal components and a passive eavesdropper node. The relay and destination receive signals from the source on two orthogonal channels such that the destination also receives transmi ... Full text Cite

Low complexity essentially maximum likelihood decoding of perfect space-time block codes

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · September 23, 2009 Perfect space-time block codes (STBCs) were first introduced by Oggier et al. to have full rate, full diversity and non-vanishing determinant. A maximum likelihood decoder based on the sphere decoder has been used for efficient decoding of perfect STBCs. H ... Full text Cite

A MIMO-OFDM channel estimation scheme utilizing complementary sequences

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · September 23, 2009 We present a pilot-assisted method for estimating the frequency selective channel in a MIMO-OFDM system. The pilot sequence is designed using the DFT of the Golay complementary sequences. Novel exploitation of the perfect autocorrelation property of Golay ... Full text Cite

Sidelobe suppression in a desired range/Doppler interval

Journal Article IEEE National Radar Conference - Proceedings · September 11, 2009 We present simple methods for constructing radar waveforms whose ambiguity functions are free of sidelobes inside a desired range or Doppler interval. We exploit the time-frequency duality between pulse amplitude modulation (PAM) and orthogonal frequency d ... Full text Cite

Practical quantum fault tolerance

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · September 10, 2009 The standard approach to quantum fault tolerance is to calculate error thresholds on basic gates in the limit of arbitrarily many concatenation levels. In contrast this paper takes the number of qubits and the target implementation accuracy as given, and p ... Full text Cite

Secrecy capacity of a class of orthogonal relay eavesdropper channels

Journal Article Eurasip Journal on Wireless Communications and Networking · September 2, 2009 The secrecy capacity of relay channels with orthogonal components is studied in the presence of an additional passive eavesdropper node. The relay and destination receive signals from the source on two orthogonal channels such that the destination also rec ... Full text Cite

Linear diversity-embedding STBC: Design issues and applications

Journal Article IEEE Transactions on Communications · July 23, 2009 We design a novel class of space-time codes, called linear diversity-embedding space-time block codes (LDE-STBC) where a high-rate STBC is linearly superimposed on a highdiversity STBC without requiring channel knowledge at the transmitter. In applying thi ... Full text Cite

Channel estimation for MIMO-OFDM using complementary codes

Journal Article RWS 2009 IEEE Radio and Wireless Symposium, Proceedings · July 21, 2009 We present a pilot-assisted method for estimating the frequency selective channel in a MIMO-OFDM (Multiple Input Multiple Output - Orthogonal Frequency Division Multiplexing) system. The pilot sequence is designed using the DFT (Discrete Fourier Transform) ... Full text Cite

Bounds and lattice-based transmission strategies for the phase-faded dirty-paper channel

Journal Article IEEE Transactions on Wireless Communications · July 1, 2009 We consider a fading version of the dirty-paper problem, as proposed by Grover and Sahai. In this formulation, the various signals involved are complex-valued, and the interference (known only to the transmitter) is multiplied by a random complex-valued co ... Full text Cite

Fusion Frames: Existence and Construction

Journal Article · June 30, 2009 Fusion frame theory is an emerging mathematical theory that provides a natural framework for performing hierarchical data processing. A fusion frame is a frame-like collection of subspaces in a Hilbert space, thereby generalizing the concept of a frame for ... Link to item Cite

On maximizing coverage in Gaussian relay channels

Journal Article IEEE Transactions on Information Theory · June 17, 2009 Results for Gaussian relay channels typically focus on maximizing transmission rates for given locations of the source, relay, and destination. We introduce an alternative perspective, where the objective is maximizing coverage for a given rate. The new ob ... Full text Cite

Optimal rate-reliability-delay tradeoff in networks with composite links

Journal Article IEEE Transactions on Communications · June 16, 2009 Networks need to accommodate diverse applications with different Quality-of-Service (QoS) requirements. New ideas at the physical layer are being developed for this purpose, such as diversity embedded coding, which is a technique that combines high rates w ... Full text Cite

Performance of the golden code in the presence of polarization diversity

Journal Article Proceedings of the 2009 Australian Communications Theory Workshop, AusCTW 2009 · June 8, 2009 The performance of a multiple-input multipleoutput (MIMO) system depends strongly on the scattering environment and antenna spacing. The use of dual-polarized antennas is a promising alternative both in terms of diversity and effective use of space. In thi ... Full text Cite

Range sidelobe suppression in a desired Doppler interval

Journal Article 2009 International Waveform Diversity and Design Conference Proceedings, WDD 2009 · April 23, 2009 We present a novel method of constructing a Doppler resilient pulse train of Golay complementary waveforms, for which the range sidelobes of the pulse train ambiguity function vanish inside a desired Doppler interval. This is accomplished by coordinating t ... Full text Cite

MIMO-OFDM channel estimation using golay complementary sequences

Journal Article 2009 International Waveform Diversity and Design Conference Proceedings, WDD 2009 · April 23, 2009 We present a pilot-assisted method for estimating the frequency selective channel in a MIMO-OFDM (Multiple Input Multiple Output - Orthogonal Frequency Division Multiplexing) system. The pilot sequence is designed using the DFT (Discrete Fourier Transform) ... Full text Cite

Energy-efficient video transmission scheduling for wireless peer-to-peer live streaming

Journal Article 2009 6th IEEE Consumer Communications and Networking Conference, CCNC 2009 · April 9, 2009 The Peer-to-Peer (P2P) streaming has shown as an effective solution for wireline video applications, while for the wireless video streaming applications, the limited radio resource and battery energy are the main constraints on the way of P2P applications. ... Full text Cite

Optimal transmission scheduling for scalable wireless video broadcast with rateless erasure correction code

Journal Article 2009 6th IEEE Consumer Communications and Networking Conference, CCNC 2009 · April 9, 2009 With the advances in wireless technology and explosive growth of mobile devices and wireless networks, mobile TV is becoming a popular application. The main technical challenge to wireless video broadcast is to provide the best quality of service possible ... Full text Cite

New rate-2 STBC design for 2 TX with reduced-complexity maximum likelihood decoding

Journal Article IEEE Transactions on Wireless Communications · April 1, 2009 We propose a new full-rate space-time block code (STBC) for two transmit antennas which can be designed to achieve maximum diversity or maximum capacity while enjoying optimized coding gain and reduced-complexity maximum-likelihood (ML) decoding. The maxim ... Full text Cite

Chirp sensing codes: Deterministic compressed sensing measurements for fast recovery

Journal Article Applied and Computational Harmonic Analysis · March 1, 2009 Compressed sensing is a novel technique to acquire sparse signals with few measurements. Normally, compressed sensing uses random projections as measurements. Here we design deterministic measurements and an algorithm to accomplish signal recovery with com ... Full text Cite

Finding needles in compressed haystacks

Chapter · January 1, 2009 In this chapter, we show that compressed learning, learning directly in the compressed domain, is possible. In particular, we provide tight bounds demonstrating that the linear kernel SVM's classifier in the measurement domain, with high probability, has t ... Full text Cite

Space-Time Coding and Application in WiMAX

Chapter · January 1, 2009 Next-generation wireless systems aim to support both voice and high capacity flexible data services with limited bandwidth. Multiplicative and additive distortions inherent to the wireless medium make this difficult, and extensive research efforts are focu ... Cite

Code diversity in multiple antenna wireless communication

Journal Article IEEE Journal on Selected Topics in Signal Processing · 2009 The standard approach to the design of individual space-time codes is based on optimizing diversity and coding gains. This geometric approach leads to remarkable examples, such as perfect space-time block codes (Perfect space-time block codes. F. Oggier , ... Full text Cite

Efficient and robust compressed sensing using optimized expander graphs

Journal Article IEEE Transactions on Information Theory · January 1, 2009 Expander graphs have been recently proposed to construct efficient compressed sensing algorithms. In particular, it has been shown that any n-dimensional vector that is k-sparse can be fully recovered using O(k log n) measurements and only O(k log n) simpl ... Full text Cite

Multiuser detection of alamouti signals

Journal Article IEEE Transactions on Communications · January 1, 2009 In a MIMO multiple-access channel where users employ Space-Time Block Codes (STBC), interference cancellation can be used to suppress co-channel interference and recover the desired signal of each user at the receiver. Leveraging the special properties of ... Full text Cite

Waveform diversity in radar signal processing: A focus on the use and control of degrees of freedom

Journal Article IEEE Signal Processing Magazine · January 1, 2009 Complementary waveforms developed by Golay are conceived to improve the sensitivity of far infrared spectrometry, which is similar to those developed by Tseng and Liu to analyze acoustic surface wave phenomena. In such a matrix, phase coded waveforms index ... Full text Cite

Robust dimension reduction, fusion frames, and Grassmannian packings

Journal Article Applied and Computational Harmonic Analysis · January 1, 2009 We consider estimating a random vector from its measurements in a fusion frame, in presence of noise and subspace erasures. A fusion frame is a collection of subspaces, for which the sum of the projection operators onto the subspaces is bounded below and a ... Full text Cite

Waveform-agile sensing and processing

Journal Article IEEE Signal Processing Magazine · January 1, 2009 The six articles in this special issue focus on waveform-agile sensing and processing. © 2009 IEEE. ... Full text Cite

Channel Estimation for MIMO-OFDM using Complementary Codes

Conference RWS: 2009 IEEE RADIO AND WIRELESS SYMPOSIUM · 2009 Cite

A Sublinear Algorithm for Sparse Reconstruction with 2 Recovery Guarantees

Conference 2009 3RD IEEE INTERNATIONAL WORKSHOP ON COMPUTATIONAL ADVANCES IN MULTI-SENSOR ADAPTIVE PROCESSING (CAMSAP) · 2009 Cite

Golay Complementary Waveforms for Sparse Delay-Doppler Radar Imaging

Conference 2009 3RD IEEE INTERNATIONAL WORKSHOP ON COMPUTATIONAL ADVANCES IN MULTI-SENSOR ADAPTIVE PROCESSING (CAMSAP) · 2009 Cite

Experiments with compressively sampled images and a new debluring-denoising algorithm

Journal Article Proceedings - 10th IEEE International Symposium on Multimedia, ISM 2008 · December 1, 2008 In this paper we will examine the effect of different parameters in the quality of real compressively sampled images in the compressed sensing framework. We will select a variety of different real images of different types and test the quality of the recov ... Full text Cite

Unitary design of radar waveform diversity sets

Journal Article Conference Record - Asilomar Conference on Signals, Systems and Computers · December 1, 2008 In this work, multiple radar waveforms are simultaneously transmitted, emitted from different "virtual" antennas. The goal is to process the returns in such a way that the overall ambiguity function is a sum of ambiguity functions better approximating the ... Full text Cite

Cognitive decoding and the Golden code

Journal Article European Signal Processing Conference · December 1, 2008 Space time signal processing starts with a system of linear equations where signals are multiplied by channel gains, and the standard criteria for the design of space time codes focus on differences between codewords at the transmitter. The value of algebr ... Cite

Network resource allocation for competing multiple description transmissions

Journal Article GLOBECOM - IEEE Global Telecommunications Conference · December 1, 2008 To provide real-time multimedia services over a network is challenging due to the stringent delay requirements in the presence of complex network dynamics. Yet such services are beginning to be deployed over best effort networks. Multiple description (MD) ... Full text Cite

Content-aware distortion-fair video streaming in networks

Journal Article GLOBECOM - IEEE Global Telecommunications Conference · December 1, 2008 Internet is experiencing an explosive growth of video traffic. Given the limited network bandwidth resources, how to provide Internet users with good video playback quality is a key problem. For video clips competing bandwidth, we propose an approach of Co ... Full text Cite

Diversity embedded codes: Theory and practice

Journal Article IEEE Journal on Selected Topics in Signal Processing · December 1, 2008 Diversity embedded codes are high-rate space-time codes that have a high-diversity code embedded within them. They allow a form of communication where the high-rate code opportunistically takes advantage of good channel realizations while the embedded high ... Full text Cite

Complementary codes based channel estimation for MIMO-OFDM systems

Journal Article 46th Annual Allerton Conference on Communication, Control, and Computing · December 1, 2008 We present a pilot-assisted method for estimating the frequency selective channel in a MIMO-OFDM (Multiple Input Multiple Output - Orthogonal Frequency Division Multiplexing) system. The pilot sequence is designed using the DFT (Discrete Fourier Transform) ... Full text Cite

Bounds on the MMSE of "bad" LDPC codes at rates above capacity

Journal Article 46th Annual Allerton Conference on Communication, Control, and Computing · December 1, 2008 We present bounds on the minimum mean square error (MMSE) of LDPC codes at rates above capacity. One potential application for MMSE estimation involves cooperative communication. A relay following a compress-and-forward (CF) strategy could first compute an ... Full text Cite

Embedded rank distance codes for ISI channels

Journal Article IEEE Transactions on Information Theory · November 10, 2008 Designs for transmit alphabet constrained space-time codes naturally lead to questions about the design of rank distance codes. Recently, diversity embedded multilevel space-time codes for flat-fading channels have been designed from sets of binary matrice ... Full text Cite

Video transmission scheduling for Peer-to-Peer live streaming systems

Journal Article 2008 IEEE International Conference on Multimedia and Expo, ICME 2008 - Proceedings · October 23, 2008 For Internet based video broadcasting applications such as IPTV, the Peer-to-Peer (P2P) streaming scheme has been found to be an effective solution. An important issue in live broadcasting is to avoid playback buffer underflow. How to utilize the playback ... Full text Cite

Bayesian analysis of interference cancellation for Alamouti multiplexing

Journal Article IEEE Transactions on Information Theory · October 9, 2008 Space-time codes built out of Alamouti components have been adopted in wireless standards such as UMTS, IEEE 802.11n, and IEEE 802.16, where they facilitate higher data rates through multiplexing of parallel data streams and the addition of two or more ant ... Full text Cite

Multilevel diversity-embedded space-time codes for video broadcasting over WiMAX

Journal Article IEEE International Symposium on Information Theory - Proceedings · September 29, 2008 Advances in wireless technologies, such as WiMAX [1], allow high data rates and high reliability through the use of MIMO-OFDM. However, they are not optimally designed for broadcasting. The nature of the wireless medium may cause an entire frame to be in o ... Full text Cite

Code diversity in multiple antenna wireless communication

Journal Article IEEE International Symposium on Information Theory - Proceedings · September 29, 2008 The standard approach to the design of individual space-time codes is based on optimizing diversity and coding gain. This geometric approach leads to remarkable examples, such as the Golden Code, for which the complexity of Maximum Likelihood (ML) decoding ... Full text Cite

A fast reconstruction algorithm for deterministic compressive sensing using second order reed-muller codes

Journal Article CISS 2008, The 42nd Annual Conference on Information Sciences and Systems · September 22, 2008 This paper proposes a deterministic compressed sensing matrix that comes by design with a very fast reconstruction algorithm, in the sense that its complexity depends only on the number of measurements n and not on the signal dimension N. The matrix constr ... Full text Cite

CISS 2008, The 42nd Annual Conference on Information Sciences and Systems: Welcome

Journal Article CISS 2008, The 42nd Annual Conference on Information Sciences and Systems · September 22, 2008 Full text Cite

Fusion frames and robust dimension reduction

Journal Article CISS 2008, The 42nd Annual Conference on Information Sciences and Systems · September 22, 2008 We consider the linear minimum meansquared error (LMMSE) estimation of a random vector of interest from its fusion frame measurements in presence noise and subspace erasures. Each fusion frame measurement is a low-dimensional vector whose elements are inne ... Full text Cite

Application of Doppler resilient complementary waveforms to target tracking

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · September 16, 2008 The use of complementary codes as a means of reducing radar range sidelobes is well-known, but lack of resilience to Doppler is often cited as a reason not to deploy them. This work describes techniques for providing Doppler resilience with an emphasis on ... Full text Cite

Doppler resilient Golay complementary waveforms

Journal Article IEEE Transactions on Information Theory · September 15, 2008 We describe a method of constructing a sequence (pulse train) of phase-coded waveforms, for which the ambiguity function is free of range sidelobes along modest Doppler shifts. The constituent waveforms are Golay complementary waveforms which have ideal am ... Full text Cite

The Icosian code and the E8 lattice: A new 4 × 4 space-time code with nonvanishing determinant

Journal Article IEEE Transactions on Information Theory · August 1, 2008 This paper introduces a new rate-2, full-diversity space-time code for four transmit antennas and one receive antenna. The 4 × 4 codeword matrix consists of four 2 × 2 Alamouti blocks with entries from Q(i,√5), and these blocks can be viewed as quaternions ... Full text Cite

Boolean functions, projection operators, and quantum error correcting codes

Journal Article IEEE Transactions on Information Theory · April 1, 2008 This paper describes a fundamental correspondence between Boolean functions and projection operators in Hilbert space. The correspondence is widely applicable, and it is used in this paper to provide a common mathematical framework for the design of both a ... Full text Cite

Elastic Service Availability: Utility Framework and Optimal Provisioning

Journal Article IEEE Journal on Selected Areas in Communications · January 1, 2008 Service availability is one of the most closely scrutinized metrics in offering network services. It is important to cost effectively provision a managed and differentiated network with various service availability guarantees under a unified platform. In p ... Full text Cite

On the achievable efficiency-fairness tradeoff in utility-optimal MAC protocols

Journal Article IEICE Transactions on Communications · January 1, 2008 We use the network utility maximization (NUM) framework to create an efficient and fair medium access control (MAC) protocol for wireless networks. By adjusting the parameters in the utility objective functions of NUM problems, we control the tradeoff betw ... Full text Cite

Rate-achievability strategies for two-hop interference flows

Journal Article 46th Annual Allerton Conference on Communication, Control, and Computing · January 1, 2008 We consider a basic model for two-hop transmissions of two information flows which interfere with each other. In this model, two sources simultaneously transmit to two relays (in the first hop), which then simultaneously transmit to two destinations (in th ... Full text Cite

Diversity embedded space-time codes

Journal Article IEEE Transactions on Information Theory · January 1, 2008 Rate and diversity impose a fundamental tradeoff in wireless communication. High-rate space-time codes come at a cost of lower reliability (diversity), and high reliability (diversity) implies a lower rate. However, wireless networks need to support applic ... Full text Cite

Boolean functions, projection operators and quantum error correcting codes

Journal Article IEEE International Symposium on Information Theory - Proceedings · December 1, 2007 This paper describes a common mathematical framework for the design of additive and non-additive Quantum Error Correcting Codes. It is based on a correspondence between boolean functions and projection operators. The new framework extends to operator quant ... Full text Cite

Rank distance codes for ISI channels

Journal Article Proceedings of the 2007 IEEE Information Theory Workshop on Information Theory for Wireless Networks, ITW · December 1, 2007 Designs for transmit alphabet constrained space-time codes naturally lead to questions about the design of rank distance codes. Recently, diversity embedded multi-level space-time codes for flat fading channels have been designed by using sets of binary ma ... Full text Cite

Doppler resilience, reed-müller codes and complementary waveforms

Journal Article Conference Record - Asilomar Conference on Signals, Systems and Computers · December 1, 2007 While the use of complementary waveforms has been considered as a technique for providing essentially perfect range sidelobe performance in radar systems, its lack of resilience to Doppler is often cited as a reason not to deploy it. This work describes an ... Full text Cite

Doppler resilient golay complementary pairs for radar

Journal Article IEEE Workshop on Statistical Signal Processing Proceedings · December 1, 2007 We present a systematic way of constructing a Doppler resilient sequence of Golay complementary waveforms for radar, for which the composite ambiguity function maintains ideal shape at small Doppler shifts. The idea is to determine a sequence of Golay pair ... Full text Cite

Diversity gains across line of sight and rich scattering environments from space-polarization-time codes

Journal Article Proceedings of the 2007 IEEE Information Theory Workshop on Information Theory for Wireless Networks, ITW · December 1, 2007 Space-time codes built out of Alamouti components have been adopted in wireless standards such as UMTS, IEEE 802.11n and IEEE 802.16 where they facilitate higher data rates through multiplexing of parallel data streams and the addition of two or more anten ... Full text Cite

On maximizing coverage in Gaussian relay networks

Journal Article Proceedings of the 2007 IEEE Information Theory Workshop on Information Theory for Wireless Networks, ITW · December 1, 2007 Results for Gaussian relay channels typically focus on maximizing transmission rates for given locations of the source, relay and destination. We consider an alternative approach, focusing on maximizing coverage for a given rate. This novel perspective ena ... Full text Cite

Fast decoding of the golden code by diophantine approximation

Journal Article 2007 IEEE Information Theory Workshop, ITW 2007, Proceedings · December 1, 2007 The Golden Code is incorporated in the IEEE 802.16 standard and is representative of a large class of space-time codes where performance is determined by the difficulty of solving an associated Diophantine approximation problem. This paper develops a new a ... Full text Cite

Congestion control in networks with delay sensitive traffic

Journal Article GLOBECOM - IEEE Global Telecommunications Conference · December 1, 2007 We study the congestion control in a network where the users may have different types of traffic, such as the traffic with fixed/variable rate, delay sensitive/insensitive, etc. To reflect the different requirements on delay by different applications, expl ... Full text Cite

Optimal provisioning of elastic service availability

Journal Article Proceedings - IEEE INFOCOM · September 4, 2007 Service availability is one of the most closely scrutinized metrics in offering network services. The network vendor can earn more revenue from the customers by guaranteeing higher service availability at the cost of higher operational expense. It is impor ... Full text Cite

Optimal rate-reliability-delay tradeoff in networks with composite links

Journal Article Proceedings - IEEE INFOCOM · September 4, 2007 Networks need to accommodate diverse applications with different Quality-of-Service (QoS) requirements. New ideas at the physical layer are being developed for this purpose, such as diversity embedded coding, which is a technique that combines high rates w ... Full text Cite

Improving detection in sea clutter using waveform scheduling

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · August 6, 2007 In this paper, we propose a method to exploit waveform agility in modern radars to improve performance in the challenging task of detecting small targets on the ocean surface in heavy clutter. The approach exploits the compound-Gaussian model for sea clutt ... Full text Cite

Applications of LDPC codes to the wiretap channel

Journal Article IEEE Transactions on Information Theory · August 1, 2007 With the advent of quantum key distribution (QKD) systems, perfect (i.e., information-theoretic) security can now be achieved for distribution of a cryptographic key. QKD systems and similar protocols use classical error-correcting codes for both error cor ... Full text Cite

Reverse-engineering MAC: A non-cooperative game model

Journal Article IEEE Journal on Selected Areas in Communications · August 1, 2007 This paper reverse-engineers backoff-based random-access MAC protocols in ad-hoc networks. We show that the contention resolution algorithm in such protocols is implicitly participating in a non-cooperative game. Each link attempts to maximize a selfish lo ... Full text Cite

Utility-optimal random-access control

Journal Article IEEE Transactions on Wireless Communications · July 1, 2007 This paper designs medium access control (MAC) protocols for wireless networks through the network utility maximization (NUM) framework. A network-wide utility maximization problem is formulated, using a collision/persistenceprobabilistic model and alignin ... Full text Cite

Adaptive waveform design for improved detection of low-RCS targets in heavy sea clutter

Journal Article IEEE Journal on Selected Topics in Signal Processing · June 1, 2007 The dynamic adaptation of waveforms for transmission by active radar has been facilitated by the availability of waveform-agile sensors. In this paper, we propose a method to employ waveform agility to improve the detection of low radar-cross section (RCS) ... Full text Cite

Pilot designs for consistent frequency-offset estimation in OFDM systems

Journal Article IEEE Transactions on Communications · May 1, 2007 This paper presents pilot designs for consistent frequency-offset estimation of orthogonal frequency-division multiplexing systems in frequency-selective fading channels. We describe two design approaches, namely, consistency in the probabilistic sense and ... Full text Cite

A simple signal processing architecture for instantaneous radar polarimetry

Journal Article IEEE Transactions on Information Theory · April 1, 2007 This paper describes a new radar primitive that enables instantaneous radar polarimetry at essentially no increase in signal processing complexity. This primitive coordinates transmission of distinct waveforms on orthogonal polarizations and applies a unit ... Full text Cite

MIMO wireless communications

Journal Article MIMO Wireless Communications · January 1, 2007 Multiple-input multiple-output (MIMO) technology constitutes a breakthrough in the design of wireless communications systems, and is already at the core of several wireless standards. Exploiting multipath scattering, MIMO techniques deliver significant per ... Full text Cite

Space-time coding and application in WiMAX

Chapter · January 1, 2007 Next-generation wireless systems aim to support both voice and high capacity flexible data services with limited bandwidth. Multiplicative and additive distortions inherent to the wireless medium make this difficult, and extensive research efforts are focu ... Cite

Layering as optimization decomposition: A mathematical theory of network architectures

Journal Article Proceedings of the IEEE · January 1, 2007 Network protocols in layered architectures have historically been obtained on an ad hoc basis, and many of the recent cross-layer designs are also conducted through piecemeal approaches. Network protocol stacks may instead be holistically analyzed and syst ... Full text Cite

Reverse engineering MAC

Journal Article 2006 4th International Symposium on Modeling and Optimization in Mobile, Ad Hoc and Wireless Networks, WiOpt 2006 · December 1, 2006 This paper reverse engineers backoff-based random-access MAC protocols in ad-hoc networks. We show that contention resolution algorithm in such protocols is implicitly participating in a non-cooperative game. Each link attempts to maximize a selfish local ... Full text Cite

Instantaneous radar polarimetry with multiple dually-polarized antennas

Journal Article Conference Record - Asilomar Conference on Signals, Systems and Computers · December 1, 2006 Fully Polarimetric radar systems are capable of simultaneously transmitting and receiving in two orthogonal polarizations. Instantaneous radar polarimetry exploits both polarization modes of a dually-polarized radar transmitter and receiver on a pulse by p ... Full text Cite

New full-diversity high-rate space-time block codes based on selective power scaling

Journal Article European Signal Processing Conference · December 1, 2006 We design a new rate-5/4 full-diversity orthogonal STBC for QPSK and 2 transmit antennas by enlarging the signalling set from the set of quaternions used in the Alamouti [1] code. Selective power scaling of information symbols is used to guarantee full-div ... Cite

Effective coding gain for space-time codes

Journal Article IEEE International Symposium on Information Theory - Proceedings · December 1, 2006 The performance of space-time codes is evaluated in terms of diversity gain and coding gain, two measures which describe the worst-case pairwise error probability between codewords at high signal-to-noise ratio (SNR). We introduce the concept of effective ... Full text Cite

The icosian code and the e8 lattice: A new 4 × 4 space-time code with non-vanishing determinant

Journal Article IEEE International Symposium on Information Theory - Proceedings · December 1, 2006 This paper introduces a new full-rate, full-diversity space-time code for 4 transmit antennas. The 4 × 4 codeword matrix consists of four 2 × 2 Alamouti blocks with entries from Q(i, √5), and these blocks can be viewed as quaternions which in turn represen ... Full text Cite

Network utility maximization and price-based distributed algorithms for rate-reliability tradeoff

Journal Article Proceedings - IEEE INFOCOM · December 1, 2006 The current framework of network utility maximization for rate allocation and its price-based algorithms assumes that each link provides a fixed-size transmission 'pipe' and each user's utility is a function of transmission rate only. These assumptions bre ... Full text Cite

Utility-optimal medium access control: Reverse and forward engineering

Journal Article Proceedings - IEEE INFOCOM · December 1, 2006 This paper analyzes and designs medium access control (MAC) protocols for wireless ad-hoc networks through the network utility maximization (NUM) framework. We first reverse-engineer the current exponential backoff (EB) type of MAC protocols such as the BE ... Full text Cite

Jointly optimal congestion and medium access control in ad hoc wireless networks

Journal Article IEEE Vehicular Technology Conference · December 1, 2006 We study joint end-to-end congestion control and per-link medium access control (MAC) in ad-hoc wireless networks. We use a network utility maximization formulation, in which by adjusting the types of utility functions, we can accommodate multi-class servi ... Full text Cite

Layering as optimization decomposition: Framework and examples

Journal Article 2006 IEEE Information Theory Workshop, ITW 2006 · November 21, 2006 Network protocols in layered architectures have historically been obtained primarily on an ad-hoc basis. Recent research has shown that network protocols may instead be holistically analyzed and systematically designed as distributed solutions to some glob ... Cite

Price-based distributed algorithms for rate-reliability tradeoff in network utility maximization

Journal Article IEEE Journal on Selected Areas in Communications · May 1, 2006 The current framework of network utility maximization for rate allocation and its price-based algorithms assumes that each link provides a fixed-size transmission "pipe" and each user's utility is a function of transmission rate only. These assumptions bre ... Full text Cite

The finite Heisenberg-Weyl groups in radar and communications

Journal Article Eurasip Journal on Applied Signal Processing · April 19, 2006 We investigate the theory of the finite Heisenberg-Weylgroup in relation to the development of adaptive radar and to theconstruction of spreading sequences and error-correcting codes incommunications. We contend that this group can form the basis forthe re ... Full text Cite

Jointly optimal congestion and contention control based on network utility maximization

Journal Article IEEE Communications Letters · March 1, 2006 We study joint end-to-end congestion control and per-link medium access control (MAC) in ad-hoc networks. We use a network utility maximization formulation, in which by adjusting the types of utility functions, we can accommodate multi-class services as we ... Full text Cite

Novel full-diversity high-rate STBC for 2 and 4 transmit antennas

Journal Article IEEE Communications Letters · March 1, 2006 We design a new rate-5/4 full-diversity orthogonal space-time block code (STBC) for QPSK and 2 transmit antennas (TX) by enlarging the signalling set from the set of quaternions used in the Alamouti [1] code. Selective power scaling of information symbols ... Full text Cite

Diversity in wireless systems

Journal Article · January 1, 2006 Introduction The main impairment in wireless channels is fading or random fluctuation of the signal level. This signal fluctuation happens across time, frequency, and space. Diversity techniques provide the receiver with multiple independent looks at the s ... Full text Cite

Introduction to space-time codes

Journal Article · January 1, 2006 Introduction Information-theoretic analysis by Foschini (1996) and by Telatar (1999) shows that multiple antennas at the transmitter and receiver enable very high rate wireless communication. Space-time codes, introduced by Tarokh. (1998), improve the reli ... Full text Cite

Cross layer utility of diversity embedded codes

Journal Article 2006 IEEE Conference on Information Sciences and Systems, CISS 2006 - Proceedings · January 1, 2006 Diversity embedded codes are opportunistic codes designed for the wireless fading channel. They are high-rate space-time codes which have embedded within them a high-diversity (low rate) code. In this paper, we focus on the application of diversity embedde ... Full text Cite

Greetings

Journal Article 2006 IEEE Conference on Information Sciences and Systems, CISS 2006 - Proceedings · January 1, 2006 Full text Cite

Layering as optimization decomposition: Current status and open issues

Journal Article 2006 IEEE Conference on Information Sciences and Systems, CISS 2006 - Proceedings · January 1, 2006 Network protocols in layered architectures have historically been obtained on an ad-hoc basis, and much of the recent cross-layer designs are conducted through piecemeal approaches. Network protocols may instead be holistically analyzed and systematically ... Full text Cite

Robust pilot design for consistent carrier frequency offset estimation

Journal Article Proceedings - IEEE Military Communications Conference MILCOM · January 1, 2006 Consistent pilot designs [6] for carrier frequency offset (CFO) estimation eliminate ambiguity in the noise-free estimation metric trajectory regardless of the channel impulse response. Their importance is more pronounced in emergency and disaster situatio ... Full text Cite

Layering as optimization decomposition: Questions and answers

Journal Article Proceedings - IEEE Military Communications Conference MILCOM · January 1, 2006 Network protocols in layered architectures have historically been obtained on an ad-hoc basis, and much of the recent cross-layer designs are conducted through piecemeal approaches. Network protocols may instead be holistically analyzed and systematically ... Full text Cite

Pilot designs for consistent frequency offset estimation in OFDM systems

Journal Article IEEE International Conference on Communications · January 1, 2006 This paper presents pilot designs for consistent frequency offset estimation of OFDM systems in frequencyselective fading channels. We describe two design approaches, namely consistency in the probabilistic sense and absolute consistency. Existing preamble ... Full text Cite

Nonintersecting subspaces based on finite alphabets

Journal Article IEEE Transactions on Information Theory · December 1, 2005 Two subspaces of a vector space are here called "nonintersecting" if they meet only in the zero vector. Motivated by the design of noncoherent multiple-antenna communications systems, we consider the following question. How many pairwise nonintersecting Mt ... Full text Cite

On achieving capacity on the wire tap channel using LDPC codes

Journal Article IEEE International Symposium on Information Theory - Proceedings · December 1, 2005 We investigate the use of capacity and near-capacity achieving LPDC codes on the wire tap channel, where the dual conditions of reliable communications and security are required. We show that good codes for conventional channels (like BSC and BEC) also hav ... Full text Cite

Exploiting algebraic structure in cross-layer design

Journal Article 2005 International Conference on Wireless Networks, Communications and Mobile Computing · December 1, 2005 We demonstrate the value of algebraic structure to cross-layer design of multiple-antenna wireless communication systems. At the network layer we will develop techniques for multiple access (many to one) and broadcast (one to many) communication where alge ... Full text Cite

Space-time reed-muller codes for noncoherent MIMO transmission

Journal Article IEEE International Symposium on Information Theory - Proceedings · December 1, 2005 We present a family of Space-Time codes for the noncoherent MIMO channel. The codes are constructed via functions that can be considered as a generalization of boolean functions to commuting projection operators which arise in the theory of quantum stabili ... Full text Cite

Distributed algorithms for optimal rate-reliability tradeoff in networks

Journal Article IEEE International Symposium on Information Theory - Proceedings · December 1, 2005 The current framework of network utility maximization for distributed rate allocation assumes fixed channel code rates. However, by adapting the physical layer channel coding, different rate-reliability tradeoffs can be achieved on each link and for each e ... Full text Cite

Improved range-summable random variable construction algorithms

Journal Article Proceedings of the Annual ACM-SIAM Symposium on Discrete Algorithms · July 1, 2005 Range-summable universal hash functions, also known as range-summable random variables, are binary-valued hash functions which can efficiently hash single values as well as ranges of values from the domain. They have found several applications in the area ... Cite

Linear-time decodable secrecy codes for binary erasure wiretap channels

Conference 43rd Annual Allerton Conference on Communication, Control and Computing 2005 · January 1, 2005 In this paper we consider encoder and decoder design for codes achieving perfect secrecy on the wiretap channel. We consider the special case of a noiseless main channel and binary erasure channel (BEC) as the wiretapper's channel and show that it is possi ... Cite

The first order space-time reed-muller codes

Conference 43rd Annual Allerton Conference on Communication, Control and Computing 2005 · January 1, 2005 We present a family of Space-Time codes for the noncoherent MIMO channel. These space-time codes are strongly related to standard binary fist order Reed-Muller codes. In particular, their decoder can be built from several parallel decoders of first order R ... Cite

On embedded diversity codes

Conference 43rd Annual Allerton Conference on Communication, Control and Computing 2005 · January 1, 2005 Diversity-embedded codes for fading channels are high-rate codes that are de-signed so that they have a high-diversity code embedded within them [3, 4]. This is equivalent to coding the data into two streams such that the high-priority stream has higher re ... Cite

Relationships between radar ambiguity and coding theory

Journal Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings · January 1, 2005 We investigate the theory of the finite discrete Heisenberg-Weyl group in relation to the development of adaptive radar. We contend that this group can form the basis for the representation of the radar environment in terms of operators on the space of wav ... Full text Cite

A novel full-rate full-diversity STBC with application to WiMAX

Conference IEEE Vehicular Technology Conference · January 1, 2005 We 1 present a novel full-rate full-diversity orthogonal space-time block code for QPSK modulation and 4 transmit antennas based on quaternionic algebra. The code does not result in constellation expansion unlike other fullrate full-diversity codes in the ... Full text Cite

Opportunistic space-time block codes

Conference IEEE Vehicular Technology Conference · January 1, 2005 Rate and diversity impose a fundamental tradeoff in space-time coding. High-rate space-time codes come at a cost of lower diversity, and high reliability (diversity) implies a lower rate. In [2], [3], we 1 proposed a different point of view where we design ... Full text Cite

Nonintersecting subspaces based on finite alphabets

Journal Article IEEE International Symposium on Information Theory - Proceedings · October 20, 2004 Codewords were constructed subject to the constraint that the elements of the codewords use symbols from a fixed, small constellation. The subspaces constructed remain nonintersecting when lifted to the complex field. The construction shows that the codewo ... Cite

Construction and analysis of a new 4 × 4 orthogonal space-time block code

Journal Article IEEE International Symposium on Information Theory - Proceedings · October 20, 2004 The construction and the analysis of a nonlinear 4×4 full rate, full-diversity orthogonal space-time block codes was discussed. The main aspect was the design, analysis and low complexity decoding of a full rate full diversity orthogonal STBC for four tran ... Cite

Space-time signaling based on Kerdock and Delsarte-Goethals codes

Journal Article IEEE International Conference on Communications · August 30, 2004 This paper designs space-time codes for standard PSK and QAM signal constellations that have flexible rate, diversity and require no constellation expansion. Central to this construction are binary partitions of the PSK and QAM constellations that appear i ... Cite

Great expectations: The value of spatial diversity in wireless networks

Journal Article Proceedings of the IEEE · January 1, 2004 In this paper, the effect of spatial diversity on the throughput and reliability of wireless networks is examined. Spatial diversity is realized through multiple independently fading transmit/receive antenna paths in single-user communication and through i ... Full text Cite

Diversity-Embedded Space-Time Codes

Journal Article Conference Record / IEEE Global Telecommunications Conference · December 1, 2003 Rate and diversity impose a fundamental trade-off in space-time coding. High-rate space-time codes come at a cost of lower diversity, and high reliability (diversity) implies a lower rate. In this paper we explore a different point of view where we design ... Cite

Algebraic properties of space-time block codes in intersymbol interference multiple-access channels

Journal Article IEEE Transactions on Information Theory · October 1, 2003 In this paper, we study the multiple-access channel where users employ space-time block codes (STBC). The problem is formulated in the context of an intersymbol interference (ISI) multiple-access channel which occurs for transmission over frequency-selecti ... Full text Cite

Multiuser joint equalization and decoding of space-time codes

Journal Article IEEE International Conference on Communications · July 18, 2003 In this paper we study the multiple-access channel where users employ space-time block codes (STBC). The problem is formulated in the context of an inter-symbol interference (ISI) multiple-access channel. The algebraic structure of the STBC is utilized to ... Cite

On interference cancellation and high-rate space-time codes

Journal Article IEEE International Symposium on Information Theory - Proceedings · January 1, 2003 We study the design and decoding of high-rate space-time codes in two contexts. The first part of the paper examines the multiple-access channel (MAC) where users employ space-time block codes (STBC). The problem is formulated in the context of an inter-sy ... Full text Cite

Space-time processing for broadband wireless access

Journal Article IEEE Communications Magazine · September 1, 2002 We present an overview of research activities on space-time coding for broadband wireless transmission performed at AT&T Shannon Laboratory over the past two years. The emphasis is on physical layer modem algorithms such as channel estimation, equalization ... Full text Cite

The pros and cons of democracy

Journal Article IEEE Transactions on Information Theory · June 1, 2002 The concept of democracy was introduced in which the individual bits in a coarsely quantized representation of a signal were given equal weight in the approximation to the original signal. It was proved that such democratic representations could not achiev ... Full text Cite

Differential space-time coding for frequency-selective channels

Journal Article IEEE Communications Letters · June 1, 2002 In this letter we introduce two space-time transmission schemes which allow full-rate and full-diversity noncoherent communications using two transmit antennas over fading frequency-selective channels. The first scheme operates in the frequency domain wher ... Full text Cite

Finite-length MIMO decision feedback equalization for space-time block-coded signals over multipath-fading channels

Journal Article IEEE Transactions on Vehicular Technology · July 1, 2001 A finite-length optimized-delay multi-input-multi-output (MIMO) mean-square-error decision-feedback equalizer for space-time block-coded transmissions over multipath-fadingchannels is presented. Alamouti's space-time block code with two transmit and two re ... Full text Cite

Obituary. Claude Shannon (1916-2001).

Journal Article Nature · April 2001 Full text Cite

Space - Time coding and signal processing for high data rate wireless communications

Journal Article Wireless Communications and Mobile Computing · 2001 The information capacity of wireless communication systems can be increased dramatically by employing multiple transmit and receive antennas [Foschini GJ, Gans MJ. On limits of wireless communications in a fading environment when using multiple antennas. W ... Full text Cite

Further results on interference cancellation and space-time block codes

Journal Article Conference Record of the Asilomar Conference on Signals, Systems and Computers · January 1, 2001 Space-Time Blocks Codes (STBC) make use of a rich algebraic structure to provide diversity gains with small decoding complexity. In this work, we show that the rich algebraic structure of STBC reduces the hardware and software complexity of interference ca ... Full text Cite

Distance spectrum computation for equalized MIMO multipath fading channels

Journal Article 2000 IEEE Wireless Communications and Networking Conference · December 1, 2000 In this paper we estimate bit error probability bounds for finite-length delay-optimised multi-input multi-output (MIMO) equalizers. These equalizers shorten the impulse response memory of frequency-selective MIMO channels by minimizing the average energy ... Cite

Cochannel interference suppression through time/space diversity

Journal Article IEEE Transactions on Information Theory · May 1, 2000 Wireless systems are subject to a time-varying and unknown a priori combination of cochannel interference, fading, and Gaussian noise. It is well known that multiple antennas can provide diversity in space that allows system tradeoffs between interference ... Full text Cite

Abuse and Disabled People: Vulnerability or social indifference?

Journal Article Disability & Society · May 1, 2000 Full text Cite

Space-time coding and signal processing for high data rate wireless communications

Conference WIRELESS COMMUNICATION TECHNOLOGIES: NEW MULTIMEDIA SYSTEMS · 2000 Cite

Interpolation by convolutional codes, overload distortion, and the erasure channel

Journal Article IEEE Transactions on Information Theory · December 1, 1999 This paper investigates how closely randomly generated binary source sequences can be matched by convolutional code codewords. What distinguishes it from prior work is that a randomly chosen subsequence with density A is to be matched as closely as possibl ... Full text Cite

Space-time block coding for wireless communications: Performance results

Journal Article IEEE Journal on Selected Areas in Communications · March 1, 1999 We document the performance of space-time block codes [13], [14], which provide a new paradigm for transmission over Rayleigh fading channels using multiple transmit antennas. Data is encoded using a space-time block code, and the encoded data is split int ... Full text Cite

Minimal tail-biting trellises: the Golay code and more

Journal Article IEEE Transactions on Information Theory · January 1, 1999 Tail-biting trellis representations of block codes are investigated. We develop some elementary theory, and present several intriguing examples, which we hope will stimulate further developments in this field. In particular, we construct a 16-state 12-sect ... Full text Cite

A Group-Theoretic Framework for the Construction of Packings in Grassmannian Spaces

Journal Article Journal of Algebraic Combinatorics · January 1, 1999 By using totally isotropic subspaces in an orthogonal space Ω+(2i, 2), several infinite families of packings of 2k-dimensional subspaces of real 2i -dimensional space are constructed, some of which are shown to be optimal packings. A certain Clifford group ... Full text Cite

Space-time block codes from orthogonal designs

Journal Article IEEE Transactions on Information Theory · January 1, 1999 The theory of space-time block coding is presented as a simple and elegant method for transmission using multiple transmit antennas in a wireless Rayleigh/Rician environment. These codes have a very simple maximum-likelihood decoding algorithm which is onl ... Full text Cite

Recent progress in space-time block and trellis coding

Journal Article IEEE International Symposium on Information Theory - Proceedings · December 1, 1998 Techniques for transmission and reception over wireless channels using multiple transmit antennas are presented. © 1998 IEEE. ... Full text Cite

Minimal tail-biting trellises: The Golay code and more

Journal Article IEEE International Symposium on Information Theory - Proceedings · December 1, 1998 A 16-state tail-biting trellis for the binary (24,12,8) Golay code C 24 is exhibited. This tail-biting trellis is minimal. It has many other nice properties, and may be simpler to decode than the minimal conventional trellis for C24. Unwrapping this tail-b ... Full text Cite

On reducing granular distortion in multiple description quantization

Journal Article IEEE International Symposium on Information Theory - Proceedings · December 1, 1998 There is a gap of 3.07 dB between the distortion product of a multiple description quantizer and the multiple description rate distortion bound. In this paper we seek to close this gap through the design of a quantizer with smaller granular distortion. © 1 ... Full text Cite

Applications of space-time block codes and interference suppression for high capacity and high data rate wireless systems

Journal Article Conference Record of the Asilomar Conference on Signals, Systems and Computers · December 1, 1998 This paper presents a combined interference suppression and ML decoding scheme for space-time block codes that can effectively suppress interference from other co-channel users while providing each user with a diversity benefit. We consider a multiuser env ... Cite

The art of signaling: fifty years of coding theory

Journal Article IEEE Transactions on Information Theory · December 1, 1998 In 1948 Shannon developed fundamental limits on the efficiency of communication over noisy channels. The coding theorem asserts that there are block codes with code rates arbitrarily close to channel capacity and probabilities of error arbitrarily close to ... Full text Cite

Space-time codes for high data rate wireless communication: Performance criterion and code construction

Journal Article IEEE Transactions on Information Theory · December 1, 1998 We consider the design of channel codes for improving the data rate and/or the reliability of communications over fading channels using multiple transmit antennas. Data is encoded by a channel code and the encoded data is split into n streams that are simu ... Full text Cite

A modified concatenated coding scheme, with applications to magnetic data storage

Journal Article IEEE Transactions on Information Theory · December 1, 1998 When a block modulation code is concatenated with an errorcorrection code (ECC) in the standard way, the use of a modulation code with long blocklengths results in error propagation. This correspondence analyzes the performance of modified concatenation, w ... Full text Cite

A space-time coding modem for high-data-rate wireless communications

Journal Article IEEE Journal on Selected Areas in Communications · October 1, 1998 This paper presents the theory and practice of a new advanced modem technology suitable for high-data-rate wireless communications and presents its performance over a frequency-flat Rayleigh fading channel. The new technology is based on space-time coded m ... Full text Cite

The application of orthogonal designs to wireless communication

Conference 1998 Information Theory Workshop, ITW 1998 · January 1, 1998 We introduce space-block codzng, a new paradigm for transmission over Rayleigh fading channels using multiple transmit antennas. Data is encoded using a space-block code and the encoded data is split into n streams which are simultaneously transmitted usin ... Full text Cite

Wavelet Transforms That Map Integers to Integers

Journal Article Applied and Computational Harmonic Analysis · January 1, 1998 Invertible wavelet transforms that map integers to integers have important applications in lossless coding. In this paper we present two approaches to build integer to integer wavelet transforms. The first approach is to adapt the precoder of Laroia et al. ... Full text Cite

Low-rate multi-dimensional space-time codes for both slow and rapid fading channels

Journal Article IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC · December 1, 1997 We consider the design of channel codes for improving the data rate and/or the reliability of communications using multiple transmit antennas over a fading channel. It is assumed that the transmitter does not know the channel but seeks to choose a codebook ... Cite

A 2-adic approach to the analysis of cyclic codes

Journal Article IEEE Transactions on Information Theory · December 1, 1997 This paper describes how 2-adic numbers can be used to analyze the structure of binary cyclic codes and of cyclic codes defined over ℤ 2a, a ≥ 2, the ring of integers modulo 2 a. It provides a 2-adic proof of a theorem of McEliece that characterizes the po ... Full text Cite

A forbidden rate region for generalized cross constellations

Journal Article IEEE Transactions on Information Theory · December 1, 1997 An analysis of the Generalized Cross Constellation (GCC) is presented and a new perspective on its coding algorithm is described. We show how the GCC can be used to address generic sets of symbol points in any multidimensional space through an example base ... Full text Cite

Quantum error correction via codes over GF(4)

Journal Article IEEE International Symposium on Information Theory - Proceedings · December 1, 1997 The unreasonable effectiveness of quantum computing is founded on coherent quantum superposition or entanglement which allows a large number of calculations to be performed simultaneously. This coherence is lost as a quantum system interacts with its envir ... Full text Cite

Lossless image compression using integer to integer wavelet transforms

Journal Article IEEE International Conference on Image Processing · December 1, 1997 Invertible wavelet transforms that map integers to integers are important for lossless representations. In this paper, we present an approach to build integer to integer wavelet transforms based upon the idea of factoring wavelet transforms into lifting st ... Cite

Space-time codes for wireless communication

Journal Article IEEE International Symposium on Information Theory - Proceedings · December 1, 1997 The design of channel codes for improving the data rate and/or the reliability of communications over fading channels using multiple transmit antennas is considered. A design criterion is provided and is then used to design space-time codes for high data r ... Full text Cite

Quantum error correction and orthogonal geometry

Journal Article Physical Review Letters · January 20, 1997 A group theoretic framework is introduced that simplifies the description of known quantum error-correcting codes and greatly facilitates the construction of new examples. Codes are given which map 3 qubits to 8 qubits correcting 1 error, 4 to 10 qubits co ... Full text Cite

4-kerdock codes, orthogonal spreads, and extremal euclidean line-sets

Journal Article Proceedings of the London Mathematical Society · January 1, 1997 Full text Cite

Double Circulant Codes over ℤ4 and even Unimodular Lattices

Journal Article Journal of Algebraic Combinatorics · January 1, 1997 With the help of some new results about weight enumerators of self-dual codes over ℤ4 we investigate a class of double circulant codes over ℤ4, one of which leads to an extremal even unimodular 40-dimensional lattice. It is conjectured that there should be ... Full text Cite

4-kerdock codes, orthogonal spreads, and extremal euclidean line-sets

Journal Article Proceedings of the London Mathematical Society · 1997 Cite

Space-time codes for high data rate wireless communication: Performance criteria

Journal Article IEEE International Conference on Communications · January 1, 1997 We consider the design of channel codes for improving the data rate and/or the reliability of communications over fading channels using multiple transmit antennas. Here, data is encoded by a channel code and the encoded data is split into n streams that ar ... Cite

Space-time codes for high data rate wireless communication: Mismatch analysis

Journal Article IEEE International Conference on Communications · January 1, 1997 We revisit Space-Time Codes for a mobile communication system that employs multiple antennas at the base and optional antenna diversity at the mobile station. The realistic case when the channel state is not completely known is considered. It is assumed th ... Cite

Space-time codes for wireless communication: Code construction

Journal Article IEEE Vehicular Technology Conference · January 1, 1997 We consider the design of channel codes for improving the data rate and/or the reliability of communications over fading channels using multiple transmit antennas. Here, data is encoded by a channel code and the encoded data is split into n streams that ar ... Cite

Construction of a (64,237,12) Code via Galois Rings

Journal Article Designs, Codes, and Cryptography · January 1, 1997 Certain nonlinear binary codes contain more codewords than any comparable linear code presently known. These include the Kerdock and Preparata codes, which exist for all lengths 4m ≥ 16. At length 16 they coincide to give the Nordstrom-Robinson code. This ... Full text Cite

On a conjecture of Helleseth regarding pairs of binary m-sequences

Journal Article IEEE Transactions on Information Theory · December 1, 1996 Binary m-sequences are maximal-length sequences generated by shift registers of length m, that are employed in navigation, radar, and spread-spectrum communication. It is well known that given a pair of distinct /«-sequences, the crosscorrelation function ... Full text Cite

The ternary golay code, the integers mod 9, and the coxeter-todd lattice

Journal Article IEEE Transactions on Information Theory · December 1, 1996 The 12-dimensinnal Coxeter-Todd lattice can be obtained by lifting the ternary Golay code to a code over the integers mod 9 and applying Construction A. © 1996 IEEE. ... Full text Cite

Large families of quaternary sequences with low correlation

Journal Article IEEE Transactions on Information Theory · December 1, 1996 A family of quaternary (Z4-alphabet) sequences of length L = T -1, size M > L2 +3X+2, and maximum nontrivial correlation parameter Cmax < 2√L + 1 + 1 is presented. The sequence family always contains the four-phase family A. When r is odd, it includes the ... Full text Cite

Cyclic codes over ℤ4 locator polynomials, and newton's identities

Journal Article IEEE Transactions on Information Theory · December 1, 1996 Certain nonlinear binary codes contain more code-words than any comparable linear code presently known. These include the Kerdock and Preparata codes that can be very simply constructed as binary images, under the Gray map, of linear codes over ℤ4 that are ... Full text Cite

Signal design for co-channel interference suppression with applications to wireless communications

Journal Article Electro International, Conference Proceedings · January 1, 1996 Co-channel interference is a major impairment in wireless systems with channel (frequency and/or time) re-use. In practice the performance of Time Division Multiple Access (TDMA) and Frequency Division Multiple Access (FDMA) systems is limited by a few dom ... Cite

Good quantum error-correcting codes exist

Journal Article Physical Review A - Atomic, Molecular, and Optical Physics · January 1, 1996 A quantum error-correcting code is defined to be a unitary mapping (encoding) of k qubits (two-state quantum systems) into a subspace of the quantum state space of n qubits such that if any t of the qubits undergo arbitrary decoherence, not necessarily ind ... Full text Cite

Modular and p-adic cyclic codes

Journal Article Designs, Codes and Cryptography · July 1, 1995 This paper presents some basic theorems giving the structure of cyclic codes of length n over the ring of integers modulo pa and over the p-adic numbers, where p is a prime not dividing n. An especially interesting example is the 2-adic cyclic code of leng ... Full text Cite

Z4-linear codes obtained as projections of Kerdock and Delsarte-Goethals codes

Journal Article Linear Algebra and Its Applications · January 1, 1995 The Kerdock and Delsarte-Goethals codes can be very simply constructed as binary images under a certain natural map, called the Gray map, of linear codes over Z4, the integers modulo 4. We consider the Gray images of linear codes over Z4 obtained from the ... Full text Cite

Channel Coding Strategies for Cellular Radio

Journal Article IEEE Transactions on Vehicular Technology · January 1, 1995 To improve re-use of time/frequency slots in a cellular radio system, it is desirable for the average interference levels seen by all users to be made approximately equal. We provide constructions based on orthogonal latin squares that guarantee different ... Full text Cite

Proof of a Conjecture of Sarwate and Pursley Regarding Pairs of Binary m-Sequences

Journal Article IEEE Transactions on Information Theory · January 1, 1995 Binary m-sequences are maximal length sequences generated by shift registers of length m, that are employed in navigation, radar, and spread-spectrum communications systems, because of their crosscorrelation properties. It is well known that given a pair o ... Full text Cite

Z4-linear codes obtained as projections of Kerdock and Delsarte-Goethals codes

Journal Article Linear Algebra and Its Applications · 1995 The Kerdock and Delsarte-Goethals codes can be very simply constructed as binary images under a certain natural map, called the Gray map, of linear codes over Z4, the integers modulo 4. We consider the Gray images of linear codes over Z4 obtained from the ... Cite

Covering Properties of Convolutional Codes and Associated Lattices

Journal Article IEEE Transactions on Information Theory · January 1, 1995 The paper describes Markov methods for analyzing the expected and worst case performance of sequence-based methods of quantization. We suppose that the quantization algorithm is dynamic programming, where the current step depends on a vector of path metric ... Full text Cite

An Upper Bound for Weil Exponential Sums over Galois Rings and Applications

Journal Article IEEE Transactions on Information Theory · January 1, 1995 We present an analog of the well-known Weil-Carlitz-Uchiyama upper bound for exponential sums over finite fields for exponential sums over Galois rings. Some examples are given where the hound is tight. The bound has immediate application to the design of ... Full text Cite

On a Technique to Calculate the Exact Performance of a Convolutional Code

Journal Article IEEE Transactions on Information Theory · January 1, 1995 A Markovian technique is described to calculate the exact performance of the Viterbi algorithm used as either a channel decoder or a source encoder for a convolutional code. The probability of information bit error and the expected Hamming distortion are c ... Full text Cite

Quaternary Quadratic Residue Codes and Unimodular Lattices

Journal Article IEEE Transactions on Information Theory · January 1, 1995 We construct new self-dual and isodual codes over the integers modulo 4. The binary images of these codes under the Gray map are nonlinear, but formally self-dual. The construction involves Hensel lifting of binary cyclic codes. Quaternary quadratic residu ... Full text Cite

Channel coding for co-channel interference suppression in wireless communications

Journal Article IEEE International Conference on Communications · January 1, 1995 Co-channel interference is a major impairment in wireless systems with channel re-use. In practice the performance of time division multiple access (TDMA) and frequency division multiple access (FDMA) systems is limited by a few dominant co-channel interfe ... Cite

Channel coding for cochannel interference suppression in wireless communication systems

Journal Article IEEE Vehicular Technology Conference · January 1, 1995 Cochannel interference is a major impairment in cellular systems. In practice the performance of time and frequency division multiple access (TDMA and FDMA) systems is limited by a few dominant cochannel interferers. Conventional channel coding techniques ... Cite

Forbidden rate region for generalized cross constellations

Journal Article IEEE International Symposium on Information Theory - Proceedings · January 1, 1995 An analysis of the Generalized Cross Constellation (GCC) is presented and a new perspective on its coding algorithm is described. We show how the GCC can be used to address generic sets of symbol points in any multidimensional space through an example base ... Cite

Upper bound for some exponential sums over Galois rings and applications

Journal Article IEEE International Symposium on Information Theory - Proceedings · December 1, 1994 An upper bound for Weil-type exponential sums over Galois rings is presented together with some examples where the bound is tight. The bound may be regarded as the Galois-ring analogue of the well-known Weil-Carlitz-Uchiyama bound for exponential sums over ... Cite

Large families of quaternary sequences with low correlation

Journal Article IEEE International Symposium on Information Theory - Proceedings · December 1, 1994 A nested chain of quaternary-sequence families having low correlation values is presented. The families are suitable for application in CDMA systems employing QPSK modulation. ... Cite

Modulation codes for multi-amplitude optical recording channels

Journal Article National Conference Publication - Institution of Engineers, Australia · December 1, 1994 We consider the problem of coding for a recording channel. Traditional magnetic or optical channels employ saturation recording, where the input to the channel is a two-level waveform. A new optical recording channel has been developed that supports unsatu ... Cite

Maximal three-independent subsets of {0, 1, 2}n

Journal Article Designs, Codes and Cryptography · October 1, 1994 We consider a variant of the classical problem of finding the size of the largest cap in the r-dimensional projective geometry PG(r, 3) over the field IF3 with 3 elements. We study the maximum size f(n) of a subset S of IF3n with the property that the only ... Full text Cite

Representations of the symmetric group in deformations of the free lie algebra

Journal Article Transactions of the American Mathematical Society · January 1, 1994 We consider, for a given complex parameter a, the nonassociative product defined on the tensor algebra of á-dimensional complex vector space by the left-normed bracketing is defined recursively to be the bracketing sequence The linear subspace spanned by a ... Full text Cite

Performance of Nonuniform Constellations on the Gaussian Channel

Journal Article IEEE Transactions on Information Theory · January 1, 1994 Testing of high-speed voiceband modems has revealed a significant increase in distortion for points near the perimeter of a QAM signal constellation. This distortion increases with distance from the center of the constellation and limits performance at dat ... Full text Cite

Synchronizable Codes for the Optical OPPM Channel

Journal Article IEEE Transactions on Information Theory · January 1, 1994 Random overlapping pulse-position modulation (OPPM) sequences result in an unrecoverable error floor on both the probability of erroneous synchronization and the probability of symbol error when only chip synchronization is present It is known, however, th ... Full text Cite

The Z4-Linearity of Kerdock, Preparata, Goethals, and Related Codes

Journal Article IEEE Transactions on Information Theory · January 1, 1994 Certain notorious nonlinear binary codes contain more codewords than any known linear code. These include the codes constructed by Nordstrom-Robinson, Kerdock, Preparata, Goethals, and Delsarte-Goethals. It is shown here that all these codes can be very si ... Full text Cite

An upper bound for some exponential sums over Galois rings and applications

Journal Article IEEE International Symposium on Information Theory - Proceedings · January 1, 1994 An upper bound for Weil-type exponential sums over Galois rings is presented together with some examples where the bound is tight. The bound may be regarded as the Galois-ring analogue of the well-known Weil-Carlitz-Uchiyama bound for exponential sums over ... Full text Cite

Large families of quaternary sequences with low correlation

Journal Article IEEE International Symposium on Information Theory - Proceedings · January 1, 1994 A nested chain of quaternary-sequence families having low correlation values is presented. The families are suitable for application in CDMA systems employing QPSK modulation. © 1994 IEEE. ... Full text Cite

The Normalized Second Moment of the Binary Lattice Determined by a Convolutional Code

Journal Article IEEE Transactions on Information Theory · January 1, 1994 We calculate the per-dimension mean squared error μ(S) of the two-state convolutional code C with generator matrix [1,1 + D], for the symmetric binary source S = [0,1], and for the uniform source S = [0,1]. When S = [0,1], the quantity μ(S) is the second m ... Full text Cite

Sequence based methods for data transmission and source compression

Conference Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) · January 1, 1993 In the last 10 years the invention of trellis coded modulation has revolutionized communication over bandlimited channels and is starting to be used in magnetic storage. Part of the reason is that sophisticated signal processing systems involving finite st ... Full text Cite

A linear construction for certain kerdock and preparata codes

Journal Article Bulletin of the American Mathematical Society · January 1, 1993 The Nordstrom-Robinson, Kerdock, and (slightly modified) Pre-parata codes are shown to be linear over ℤ4, the integers mod 4. The Kerdock and Preparata codes are duals over ℤ4, and the Nordstrom-Robinson code is self-dual. All these codes are just extended ... Full text Cite

The Sperner Capacity of Linear and Nonlinear Codes for the Cyclic Triangle

Journal Article Journal of Algebraic Combinatorics: An International Journal · January 1, 1993 Shannon introduced the concept of zero-error capacity of a discrete memoryless channel. The channel determines an undirected graph on the symbol alphabet, where adjacency means that symbols cannot be confused at the receiver. The zero-error or Shannon capa ... Full text Cite

Extending the t-design concept

Journal Article Transactions of the American Mathematical Society · January 1, 1993 Let 픅 be a family of k-subsets of a υ-set V, with 1 ≤ k ≤ υ/2. Given only the inner distribution of 픅, i.e., the number of pairs of blocks that meet in j points (with j = 0, 1, …, k), we are able to completely describe the regularity with which 픅 meets an ... Full text Cite

On the apparent duality of the kerdock and preparata codes

Conference Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) · January 1, 1993 The Kerdock and extended Preparata codes are something of an enigma in coding theory since they are both Hamming-distance invariant and have weight enumerators that are MacWilliams duals just as if they were dual linear codes. In this paper, we explain, by ... Full text Cite

Channel coding strategies for cellular radio

Journal Article Proceedings of the 1993 IEEE International Symposium on Information Theory · January 1, 1993 To improve re-use of time/frequency slots in a cellular radio system, it is desirable for the average interference levels seen by all users to be made approximately equal. We provide constructions based on orthogonal Latin squares that guarantee different ... Cite

Multilevel Codes for Unequal Error Protection

Journal Article IEEE Transactions on Information Theory · January 1, 1993 In many speech and image coding schemes. some of the coded bits are extremely sensitive to channel errors while some others exhibit very little sensitivity. In order to make the best use of channel redundancy, unequal error protection (UEP) codes are neede ... Full text Cite

Further asymptotic upper bounds on the minimum distance of trellis codes

Journal Article IEEE Transactions on Information Theory · 1993 Asymptotic upper bounds on the minimum distance of trellis codes are derived. A universal bound and bounds specific to PSK and QAM signal sets are obtained. ... Full text Cite

Sperner capacity of linear and nonlinear codes for the cyclic triangle

Journal Article Proceedings of the 1993 IEEE International Symposium on Information Theory · January 1, 1993 Shannon introduced the concept of zero-error capacity of a discrete memoryless channel. The channel determines an undirected graph on the symbol alphabet, where adjacency means that symbols cannot be confused at the receiver. The zero-error or Shannon capa ... Cite

Multilevel codes for unequal error protection

Journal Article Proceedings of the 1993 IEEE International Symposium on Information Theory · January 1, 1993 In many speech and image coding schemes, some of the coded bits are extremely sensitive to channel errors while some others exhibit very little sensitivity. In order to make the best use of channel redundancy, unequal error protection (UEP) codes are neede ... Cite

Covering properties of convolutional codes and associated lattices

Journal Article Proceedings of the 1993 IEEE International Symposium on Information Theory · January 1, 1993 This talk describes methods for analyzing the expected and worst-case performance of sequence based methods of quantization. We suppose that the quantization algorithm is dynamic programming, where the current step depends on a vector of path metrics, whic ... Cite

Coding for the unsynchronized optical OPPM channel

Journal Article Proceedings of the 1993 IEEE International Conference on Communications · January 1, 1993 Random OPPM sequences result in an unrecoverable error floor on both the probability of erroneous synchronization and the probability of symbol error when only chip synchronization is present. It is known, however, that for a given sequence length M, a sub ... Cite

Normalized second moment of the binary lattice determined by a convolutional code

Journal Article Proceedings of the 1993 IEEE International Symposium on Information Theory · January 1, 1993 The output of a finite state machine is a collection of codewords that can be searched efficiently to find the optimum codeword with respect to any nonnegative measure that can be calculated on a symbol by symbol basis. Applications involving trellis codes ... Cite

Covering machines

Journal Article Discrete Mathematics · September 1, 1992 We construct 2-state covering machines from binary linear codes with a sufficiently rich subcode structure. The goal is to trade multiple covering properties for increased redundancy. We explain why the expected covering properties of covering machines sho ... Full text Cite

Quasi-symmetric designs and the Smith Normal Form

Journal Article Designs, Codes and Cryptography · June 1, 1992 We obtain necessary conditions for the existence of a 2 - (ν, k, λ) design, for which the block intersection sizes s1, s2, ..., snsatisfy s1 ≡ s2 ≡ ... ≡ sn ≡ s (mod pe),where p is a prime and the exponent e is odd. These conditions are obtained from restr ... Full text Cite

Improved Upper Bounds Concerning the Erdős-Ko-Rado Theorem

Journal Article Combinatorics, Probability and Computing · January 1, 1992 A family [formula omitted] of k-element sets of an n-set is called t-intersecting if any two of its members overlap in at least t-elements. The Erdős-Ko-Rado Theorem gives a best possible upper bound for such a family if n ≥ n0(k, t). One of the most excit ... Full text Cite

Upper Bounds for Small Trellis Codes

Journal Article IEEE Transactions on Information Theory · January 1, 1992 An upper bound on the minimum squared distance of trellis codes by packing Voronoi cells is derived, and we compare this bound with previously known bounds. The bound is tight to search results for coset codes with a small number of states. © 1992 IEEE ... Full text Cite

Covering bounds for codes

Journal Article Journal of Combinatorial Theory, Series A · January 1, 1992 Given an [n, k]R code C, and a subcode H of C with codimension j, define SHj(C) = maxx∈F2n {d(x, H) + d(x, C H)}, and define the j-norm, Sj(C) to be the minimum value of SHj(C) as H ranges over the subcodes with codimension j. We prove that if k (n + 1) > ... Full text Cite

Balanced Codes and Nonequiprobable Signaling

Journal Article IEEE Transactions on Information Theory · January 1, 1992 The problem of shaping signal constellations that are designed for the Gaussian channel is considered. The signal constellation consists of all points from some translate of a lattice A, that lie within a region $. The signal constellation is partitioned i ... Full text Cite

State-space characterization of viterbi detector path metric differences

Conference Conference Record - Asilomar Conference on Signals, Systems and Computers · January 1, 1992 In the digital implementations of maximumlikelihood detectors based upon the Viterbi algorithm, bounds on the values of path metric differences are important parameters, and various techniques have been proposed for computing such bounds. This paper addres ... Full text Cite

The mathematics of moderns

Journal Article The Mathematical Intelligencer · September 1, 1991 Full text Cite

Binary covering codes and high speed data transmission

Conference Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) · January 1, 1991 There has been a great deal of recent interest in the covering radius of binary codes. We shall describe how good covering codes can be used to make high speed data transmission more reliable. ... Full text Cite

A Strengthening of the Assmus-Mattson Theorem

Journal Article IEEE Transactions on Information Theory · January 1, 1991 Let W1 = d, w2,…, wsbe the weights of the nonzero codewords in a binary linear [n, k, d] code C, and let w'1, w'2,…, w's' be the nonzero weights in the dual code CT. Let t be an integer in the range 0 < t < d such that there are at most d — t weights w'iwi ... Full text Cite

A strengthening of the Assmus-Mattson Theorem

Journal Article · December 1, 1990 Summary form only given. Let w1 = d, w2, ..., ws be the weights of the nonzero code words in a binary linear [n, k, d] code C, and let w1′, w2′, ..., ws′ be the nonzero weights in the dual code C⊥. Let t be an integer in the range 0 < t < d such that there ... Cite

Non-equiprobable signaling on the Gaussian channel

Journal Article · December 1, 1990 Summary form only given, as follows. Many signaling schemes for the Gaussian channel are based on finite-dimensional lattices. The signal constellation consists of all lattice points within a region R, and the shape of this region determines the average si ... Cite

Binary codes and quasi-symmetric designs

Journal Article Discrete Mathematics · August 1, 1990 We obtain a new necessary condition for the existence of a 2-(υ, k, λ) design where the block intersection sizes s1,s2,...,sn satisfy s1≡s2≡...≡sn≡s( mod 2). This condition eliminates quasi-symmetric 2-(20, 10, 18) and 2-(60, 30, 58) designs. Quasi-symmetr ... Full text Cite

Nonequiprobable Signaling on the Gaussian Channel

Journal Article IEEE Transactions on Information Theory · January 1, 1990 Many signaling schemes for the Gaussian channel are based on finite-dimensional lattices. The signal constellation consists of all lattice points within a region and the shape of this region determines the average signal power. Spherical signal constellati ... Full text Cite

Covering radius and the chromatic number of Kneser graphs

Journal Article Journal of Combinatorial Theory, Series A · January 1, 1990 Let C be a binary linear code with covering radius R and let C0 be a subcode of C with codimension i. We prove that the covering radius R0 of C satisfies R0 ≤ 2R + 2i - 1, by setting up a graph coloring problem involving Kneser graphs. © 1990. ... Full text Cite

A Note Extending the Analysis of Two-Head Disk Systems to More General Seek-Time Characteristics

Journal Article IEEE Transactions on Computers · January 1, 1989 We analyze a model of a movable-head disk system with two read/write heads maintained a fixed distance d apart on each arm. Successive request-addresses are assumed to be independent random variables, uniformly distributed over the set of cylinders. The pu ... Full text Cite

Baseband Line Codes Via Spectral Factorization

Journal Article IEEE Journal on Selected Areas in Communications · January 1, 1989 We describe a method of designing baseband line codes with prescribed spectral nulls in the transmitted spectrum. These codes have the important property that the transmitted power is adjustable (with a concomitant change in spectral shape, i.e., null widt ... Full text Cite

Coset Codes for Partial Response Channels; or, Coset Codes with Spectral Nulls

Journal Article IEEE Transactions on Information Theory · January 1, 1989 Known coset codes are adapted for use on partial response channels or to generate signals with spectral nulls. By the use of methods of coset precoding and running digital sum feedback, any desired tradeoff can be achieved between the power and spectra of ... Full text Cite

Multilevel Codes and Multistage Decoding

Journal Article IEEE Transactions on Communications · January 1, 1989 Imai and Hirakawa have proposed a multilevel coding method based on binary block codes that admits a staged decoding procedure. This method has been extended to the design of codes for the Gaussian channel that admit multistage decoding procedures by Ginzb ... Full text Cite

A Multilevel Approach to the Design of DC-Free Line Codes

Journal Article IEEE Transactions on Information Theory · January 1, 1989 A multilevel approach to the design of dc-free line codes is presented. The advantages of codes designed by this method over similar codes presented by Ferreira and Blaum are the improved run length/ accumulated charge parameters, higher transmission rate, ... Full text Cite

Multi-level channel codes based on partitioning

Journal Article · December 1, 1988 Summary form only given, as follows. Imai and Hirakawa have proposed a multilevel coding method based on binary block codes that admits a staged decoding procedure. This method has been extended to the design of codes for the Gaussian channel by Ginzburg a ... Cite

COSET codes for partial response; or, codes with spectral nulls

Journal Article · December 1, 1988 Summary form only given, as follows. Known coset codes are adapted for use on partial response channels or to generate signals with spectral nulls. By use of methods of coset precoding and running digital sum feedback, any desired tradeoff can be achieved ... Cite

Multi-level trellis codes for the Gaussian channel and for channels subject to impulsive noise

Journal Article Proceedings - IEEE Military Communications Conference · December 1, 1988 The author designs multilevel trellis codes based on lattices and cosets that provide greater immunity to Gaussian noise and/or greater resistance to impulse noise than previous approaches. He shows how to calculate minimum-squared distance and path multip ... Cite

Construction of trellis-decodable error-correcting line codes

Journal Article · December 1, 1988 Summary form only given, as follows. The design of balanced error-correcting codes has received a lot of attention in recent literature. Besides their error-control capability, these codes also have power spectral densities that make them attractive for us ... Cite

Linear inequalities for covering codes

Journal Article · December 1, 1988 Summary form only given, as follows. Any code C with covering radius R must satisfy a set of linear inequalities that involve the Lloyd polynomial LR(x); these generalize the sphere bound. The syndrome graphs associated with a linear code C help to keep tr ... Cite

Optimal directory placement on disk storage devices

Journal Article Journal of the ACM (JACM) · April 1, 1988 Two mathematical models dealing with optimal placement of directories on disk devices are analyzed. Storage addresses on the disk are approximated by points in the interval [0, 1]. Requests for information on the disk are represented by a sequence of file ... Full text Cite

Symmetric Designs as the Solution of an Extremal Problem in Combinatorial Set Theory

Journal Article European Journal of Combinatorics · January 1, 1988 We apply duality in the Johnson scheme J(v, k) to give a very short proof of a theorem of Frankl and Füredi. We consider a family ℱ of k-subsets of a v-set such that ℱ is a 1-design and |x ∪ y| ⩾ λ > 0 for all x, y ∈ ℱ. We prove v ⩽ (k2 − k + λ)/λ with equ ... Full text Cite

Inequalities for Covering Codes

Journal Article IEEE Transactions on Information Theory · January 1, 1988 Any code C with covering radius R must satisfy a set of linear inequalities that involve the Lloyd polynomial LR(x); these generalize the sphere bound. The “syndrome graphs” associated with a linear code C help to keep track of low weight vectors in the sa ... Full text Cite

Baseband Trellis Codes with a Spectral Null at Zero

Journal Article IEEE Transactions on Information Theory · January 1, 1988 A method is described for modifying classical N-dimensional trellis codes to provide baseband codes that combine a spectral null at dc with significant coding gain. The information rate of the classical code is decreased by one bit, and this extra redundan ... Full text Cite

Inequalities for quasi-symmetric designs

Journal Article Journal of Combinatorial Theory, Series A · January 1, 1988 A 2-design is said to be quasi-symmetric if there are two block intersection sizes. We obtain inequalities satisfied by the parameters of a quasi-symmetric design using linear programming techniques. The same methods apply to codes with covering radius 2 w ... Full text Cite

Geometric invariants for quasi-symmetric designs

Journal Article Journal of Combinatorial Theory, Series A · January 1, 1988 Let p be an odd prime. We derive new necessary conditions for the existence of 2 - (ν, k, λ) designs where the block intersection sizes s1, s2, ..., sn satisfy s1 ≡ s2 ≡ ... ≡ sn (mod p). The method is to define a nondegenerate scalar product on a 2m-dimen ... Full text Cite

New Trellis Codes Based on Lattices and Cosets

Journal Article IEEE Transactions on Information Theory · January 1, 1987 A new technique is proposed for constructing trellis codes, which provides an alternative to Ungerboeck's method of “set partitioning.” The new codes use a signal constellation consisting of points from an n-dimensional lattice A, with an equal number of p ... Full text Cite

The application of invariant theory to the existence of quasi-symmetric designs

Journal Article Journal of Combinatorial Theory, Series A · January 1, 1987 Gleason and Mallows and Sloane characterized the weight enumerators of maximal self-orthogonal codes with all weights divisible by 4. We apply these results to obtain a new necessary condition for the existence of 2 - (v, k, λ) designs where the intersecti ... Full text Cite

An Erdös-Ko-Rado theorem for regular intersecting families of octads

Journal Article Graphs and Combinatorics · December 1, 1986 Codewords of weight 8 in the [24, 12] binary Golay code are called octads. A family ℱ of octads is said to be a regular intersecting family if ℱ is a 1-design and |x ∩ y| ≠ 0 for all x, y ∈ ℱ. We prove that if ℱ is a regular intersecting family of octads t ... Full text Cite

NEW TRELLIS CODES.

Journal Article · December 1, 1986 Summary form only given. A technique is proposed for constructing multidimensional trellis codes that provides an alternative to Ungerboeck's method of 'set partitioning. ' The new codes use a signal constellation consisting of points from an n-dimensional ... Cite

BINARY CONVOLUTIONAL CODES WITH APPLICATION TO MAGNETIC RECORDING.

Journal Article · December 1, 1986 Summary form only given. A. R. Calderbank et. al. have suggested a method of designing codes for channels with intersymbol interference, such as the magnetic recording channel. They considered an idealized model of the magnetic recording channel that leads ... Cite

Nonexistence of a Uniformly Packed [70,58,5] Code

Journal Article IEEE Transactions on Information Theory · January 1, 1986 The nonexistence of a uniformly-packed [70,58,5] code C┴ is proved by examining geometries associated with the 3-weight code C. Copyright © 1986 by The Institute of Electrical and Electronics Engineers, Inc. ... Full text Cite

Binary Convolutional Codes with Application to Magnetic Recording

Journal Article IEEE Transactions on Information Theory · January 1, 1986 Calderbank, Heegard, and Ozarow [1] have suggested a method of designing codes for channels with intersymbol interference, such as the magnetic recording channel. These codes are designed to exploit intersymbol interference. The standard method is to minim ... Full text Cite

Functions that Never Agree

Journal Article European Journal of Combinatorics · January 1, 1986 Consider functions f1, . . . , fk defined on an n-element set I with the property that if x ∈ I then f1(x), . . . , fk(x) are all distinct. We shall say that the functions f1, . . . , fk never agree. Let ρ(f1, . . . , fk) be the size of the largest subset ... Full text Cite

Partitions into even and odd block size and some unusual characters of the symmetric groups

Journal Article Proceedings of the London Mathematical Society · January 1, 1986 For each n and k, let Π(i, k) denote the poset of all partitions of n having every block size congruent to i mod k. Attach to Πn(i, k) a unique maximal or minimal element if it does not already have one, and denote the resulting poset Πn(i, k). Results of ... Full text Cite

BINARY CONVOLUTIONAL CODES WITH APPLICATION TO MAGNETIC RECORDING.

Journal Article IEEE Transactions on Information Theory · 1986 Motivated by an idealized model of the magnetic recording channel, codes were designed for a partial response channel with transfer function (1-D**N)/2 where the channel inputs are constrained to be plus or minus 1. Channel inputs are generated using a non ... Cite

70,58,5.

Journal Article IEEE Transactions on Information Theory · 1986 Uniformly packed, linear e-error-correcting codes are considered. In particular, it is shown that the nonexistence of a uniformly packed left bracket 70,58,5 right bracket code C PERPEND is proved by examining geometries associated with the 3-weight code C ... Cite

The extension to root systems of a theorem on tournaments

Journal Article Journal of Combinatorial Theory, Series A · January 1, 1986 M. G. Kendall and B. Babington-Smith proved that if a tournament p′ is obtained from a tournament p by reversing the edges of a 3-cycle then p and p′ contain the same number of 3-cycles. This theorem is the basis of a cancellation argument used by D. Zeilb ... Full text Cite

An Eight-Dimensional Trellis Code

Journal Article Proceedings of the IEEE · January 1, 1986 An 8-state trellis code is described that uses a signal constellation from the 8-dimensional Gosset lattice E8 It can be used for example to transmit data at 9.6, 14.4, and 19.2 kbits/s with a nominal coding gain of close to 6 dB. © 1986 IEEE ... Full text Cite

The geometry of two-weight codes

Journal Article Bulletin of the London Mathematical Society · January 1, 1986 We survey the relationships between two-weight linear [n, k] codes over GF(q), projective (n, k, h1, h2) sets in PG(k – 1, q), and certain strongly regular graphs. We also describe and tabulate essentially all the known examples. © 1986, Oxford University ... Full text Cite

On a Pair of Dual Subschemes of the Hamming Scheme Hn(q)

Journal Article European Journal of Combinatorics · January 1, 1985 We consider codes in the Hamming association scheme Hn(q) with interesting metric properties. We describe how a uniformly packed linear code C determines a pair of dual subschemes. The existence of this pair of subschemes is used to establish restrictions ... Full text Cite

Sequencing two Servers On a Sphere

Journal Article Communications in Statistics. Stochastic Models · January 1, 1985 We analyze a service system in which two servers move independently on the surface of the n-dimensional sphere. Requests for service arrive independently and uniformly over the surface. the ith request is to be served completely before service of the (i+l) ... Full text Cite

Four‐Dimensional Modulation With an Eight‐State Trellis Code

Journal Article AT&T Technical Journal · January 1, 1985 A trellis code is a “sliding window” method for encoding a binary data stream {ai}, ai = 0, 1, as a sequence of signal points drawn from Rn. The rule for assigning signal points depends on the state of the encoder. In this paper n = 4, and the signal point ... Full text Cite

SEQUENCING PROBLEMS IN TWO-SERVER SYSTEMS.

Journal Article Mathematics of Operations Research · January 1, 1985 We analyze a service system in which two identical servers move one at a time along a linear array of N positions. Requests for service, each designating one of the N positions, join a first-in-first queue, where processing of the nth request does not begi ... Full text Cite

ASYMPTOTIC UPPER BOUNDS ON THE MINIMUM DISTANCE OF TRELLIS CODES.

Journal Article IEEE Transactions on Communications · January 1, 1985 A trellis code is a 'sliding window' method of encoding a binary data stream as a sequence of signal points. When a trellis code is used to encode data at the rate of k bits/channel symbol, each channel input depends not only on the most recent block of k ... Full text Cite

NEW FAMILY OF CODES FOR DIAL-UP VOICE LINES.

Journal Article · December 1, 1984 Using a certain 4-dimensional lattice, a new family of codes has been constructed that has a very low error rate. Two particular codes in this family appear to be excellent candidates for use in modems operating at 9. 6 and 14. 4 kb/s, respectively, on dia ... Cite

THREE-WEIGHT CODES AND ASSOCIATION SCHEMES.

Journal Article Philips Journal of Research · December 1, 1984 Three-weight projective codes C are considered for which the restriction to C of the Hamming association scheme H//n(q) is an association scheme with three classes. Sufficient conditions are established and restrictions on the three weights of C are obtain ... Cite

Optimum Head Separation in a Disk System with Two Read/Write Heads

Journal Article Journal of the ACM (JACM) · September 20, 1984 A mathematical model of computer disk storage devices having two movable read/write heads is studied. Storage addresses are approximated by points in the continuous interval [0, 1], and requests for information on the disk are processed first-come-first-se ... Full text Cite

NEW DESCRIPTION OF TRELLIS CODES.

Journal Article IEEE Transactions on Information Theory · 1984 A trellis code is a 'sliding window' method of encoding a binary data stream as a sequence of real or complex numbers that are input to a noisy transmission channel. Ungerboeck has constructed simple trellis codes that provide the same noise immunity as is ... Cite

Increasing sequences with nonzero block sums and increasing paths in edge-ordered graphs

Journal Article Discrete Mathematics · January 1, 1984 Consider the maximum length f(k) of a (lexicographically) increasing sequence of vectors in GF(2)k with the property that the sum of the vectors in any consecutive subsequence is nonzero modulo 2. We prove that 23 48 · 2k ≤ f(k) ≤ ( 1 2 + o(1))2k. A relate ... Full text Cite

The Haemers partial geometry and the Steiner system S(5, 8, 24)

Journal Article Discrete Mathematics · January 1, 1984 Haemers has constructed a partial geometry with parameters s = 4, t = 17, and α = 2, using properties of the Hoffman-Singleton graph. We describe this geometry in terms of the Steiner system S(5, 8, 24). © 1984. ... Full text Cite

A New Description of Trellis Codes

Journal Article IEEE Transactions on Information Theory · January 1, 1984 A trellis code is a “sliding window” method of encoding a binary data stream as a sequence of real or complex numbers that are input to a noisy transmission channel. Ungerboeck has constructed simple trellis codes that provide the same noise immunity as is ... Full text Cite

Upper Bounds on the Minimum Distance of Trellis Codes

Journal Article Bell System Technical Journal · January 1, 1983 A trellis code is a “sliding window” method of encoding a binary data stream into a sequence of real numbers that are input to a noisy transmission channel. When a trellis code is used to encode data at the rate of k bits/channel symbol, each channel input ... Full text Cite

SQUARE ROOT BOUND ON THE MINIMUM WEIGHT IN QUASI-CYCLIC CODES.

Journal Article IEEE Transactions on Information Theory · 1983 The author establishes a square root bound on the minimum weight in the quasi-cyclic binary codes constructed by V. K. Bhargava, S. E. Tavares, and S. G. S. Shiva. The proof rests on viewing the codes as ideas in a group algebra over GF. ... Cite

Two-weight ternary codes and the equation y2 = 4 × 3a + 13

Journal Article Journal of Number Theory · January 1, 1983 This paper determines the parameters of all two-weight ternary codes C with the property that the minimum weight in the dual code C⊥ is at least 4. This yields a characterization of uniformly packed ternary [n, k, 4] codes. The proof rests on finding all i ... Full text Cite

UPPER BOUNDS ON THE MINIMUM DISTANCE OF TRELLIS CODES.

Journal Article The Bell System technical journal · 1983 A trellis code is a 'sliding window' method of encoding a binary data stream into a sequence of real numbers that are input to a noisy transmission channel. When a trellis code is used to encode data at the rate of k bits/channel symbol, each channel input ... Cite

A Square Root Bound on the Minimum Weight in Quasi-Cyclic Codes

Journal Article IEEE Transactions on Information Theory · January 1, 1983 We establish a square root bound on the minimum weight in the quasi-cyclic binary codes constructed by Bhargava, Tavares, and Shiva. The proof rests on viewing the codes as ideals in a group algebra over GF (4). Theorem 6 answers a question raised by F. J. ... Full text Cite

A global code invariant under the Higman-Sims group

Journal Article Journal of Algebra · January 1, 1982 Full text Cite

On uniformly packed [n, n-fc,4] codes over gf(Q) and a class of caps in ?g(k-l, q)

Journal Article Journal of the London Mathematical Society · January 1, 1982 We determine all uniformly packed [n, k, 4] codes over GF (2) and we derive a non-trivial necessary condition for the existence of uniformly packed [k, 4] codes over GF (q), where q 2 is a prime power. This condition allows us to classify uniformly packed ... Full text Cite

A Good Method of Combining Codes

Journal Article Linear Algebra and Its Applications · January 1, 1980 Let q be an odd prime power, and suppose q−1 (mod8), Let C(q) and C(q)∗ be the two extended binary quadratic residue codes (QR codes) of length q+1, and let T(q)={(a+x;b+x;a+b+x):a,b∈C(q),x∈C(q)∗}. We establish a square root bound on the minimum weight in ... Full text Cite