Scholars@Duke
Tingjun Chen

Tingjun Chen

Nortel Networks Assistant Professor of Electrical and Computer Engineering
Electrical and Computer Engineering

Selected Publications

Disaggregated machine learning via in-physics computing at radio frequency.

Journal Article Sci Adv · January 9, 2026 Modern edge devices, such as cameras, drones, and internet-of-things nodes, rely on machine learning to enable a wide range of intelligent applications. However, deploying machine learning models directly on the often resource-constrained edge devices dema ... Full text Link to item Cite

Scalable ML models and cascaded learning for efficient multi-span OSNR and GSNR prediction

Journal Article Journal of Optical Communications and Networking · January 1, 2026 Scalable and efficient methods for predicting optical transmission performance using machine learning (ML) and cascaded learning (CL) are investigated in metro multi-span optical networks. We extend the CL framework beyond multi-span power spectrum predict ... Full text Cite

Multi-span optical power spectrum prediction using cascaded learning with one-shot end-to-end measurement

Journal Article Journal of Optical Communications and Networking · January 1, 2025 Scalable methods for optical transmission performance prediction using machine learning (ML) are studied in metro reconfigurable optical add-drop multiplexer (ROADM) networks. A cascaded learning framework is introduced to encompass the use of cascaded com ... Full text Cite

Design and Testbed Deployment of Frequency-Domain Equalization Full Duplex Radios

Journal Article IEEE Transactions on Wireless Communications · January 1, 2025 Full-duplex (FD) wireless can significantly enhance spectrum efficiency but requires effective self-interference (SI) cancellers. RF SI cancellation (SIC) via frequency-domain equalization (FDE), where bandpass filters channelize the SI, is suited for inte ... Full text Cite

On the Optimization and Stability of Sectorized Wireless Networks

Journal Article IEEE Transactions on Networking · January 1, 2025 Future wireless networks need to support the increasing demands for high data rates and improved coverage. One promising solution is sectorization, where an infrastructure node is equipped with multiple sectors employing directional communication. Although ... Full text Cite

Generalized few-shot transfer learning architecture for modeling the EDFA gain spectrum

Journal Article Journal of Optical Communications and Networking · January 1, 2025 Accurate modeling of the gain spectrum in erbium-doped fiber amplifiers (EDFAs) is essential for optimizing optical network performance, particularly as networks evolve toward multi-vendor solutions. In this work, we propose a generalized few-shot transfer ... Full text Cite

Optical Link Tomography: First Field Trial and 4D Extension

Journal Article Journal of Lightwave Technology · January 1, 2025 Optical link tomography (OLT) is a rapidly evolving field that allows the multi-span, end-to-end visualization of optical power along fiber links in multiple dimensions from network endpoints, solely by processing signals received at coherent receivers. Th ... Full text Cite

Mambas: Maneuvering Analog Multi-User Beamforming using an Array of Subarrays in mmWave Networks

Conference ACM Mobicom 2024 Proceedings of the 30th International Conference on Mobile Computing and Networking · December 4, 2024 Beyond-5G and 6G wireless networks exploit the millimeter-wave (mmWave) frequency bands to achieve significantly improved data rates, and existing mmWave systems rely on analog single-user beamforming (SUBF) or hybrid multi-user beamforming (MUBF). In this ... Full text Cite

RadCloud: Real-Time High-Resolution Point Cloud Generation Using Low-Cost mmWave Radars for Aerial and Ground Vehicles

Conference ACM Mobicom 2024 Proceedings of the 30th International Conference on Mobile Computing and Networking · December 4, 2024 We demonstrate RadCloud, a real-time framework for obtaining high-resolution lidar-like 2D point clouds from low-resolution millimeter-wave (mmWave) radar data on resource-constrained platforms commonly found on unmanned aerial and ground vehicles (UAVs an ... Full text Cite

Demo: Experimentation with Mobile 28 GHz Phased Array Antenna Modules

Conference ACM Mobicom 2024 Proceedings of the 30th International Conference on Mobile Computing and Networking · December 4, 2024 We present experiments using mobile 28 GHz Phased Array Antenna Modules (PAAMs), demonstrating their ability to perform beam steering with high granularity. The mobile node contains a 64-element IBM 28 GHz PAAM along with a USRP software defined radio, all ... Full text Cite

28 GHz Phased Array Interference Measurements and Modeling for a NOAA Microwave Radiometer in Manhattan

Conference ACM Mobicom 2024 Proceedings of the 30th International Conference on Mobile Computing and Networking · December 4, 2024 A microwave radiometer (MWR) at NOAA-CESSRST in Manhattan, NYC has experienced interference from nearby sources operating in the 5G FR2 n257 band (26.50 - 29.50 GHz). In this poster, we produce interference using a mobile 28 GHz IBM Phased Array Antenna Mo ... Full text Cite

Real-time Wideband Software-defined Radio with Python Programmability based on RFSoC

Conference ACM Mobicom 2024 Proceedings of the 30th International Conference on Mobile Computing and Networking · December 4, 2024 Next-generation wireless networks necessitate large signal bandwidth to support the growing demands of high data rates, which poses significant challenges in the design of real-time radio platforms. We demonstrate SPEAR, a realtime wideband software-define ... Full text Cite

SPEAR: Software-defined Python-Enhanced RFSoC for Wideband Radio Applications

Conference ACM Mobicom 2024 Proceedings of the 30th International Conference on Mobile Computing and Networking · December 4, 2024 Next-generation wireless systems utilize large signal band-widths to meet the growing data rate demands of emerging applications and to provide enhanced resolution for wireless sensing and imaging. This poses significant challenges in the design of the und ... Full text Cite

DeepMon: Wi-Fi Monitoring Using Sub-Nyquist Sampling Rate Receivers with Deep Learning

Conference ACM Mobicom 2024 Proceedings of the 30th International Conference on Mobile Computing and Networking · December 4, 2024 Next-generation Wi-Fi networks employ large signal bandwidth to meet the demands of high data rates, which poses challenges to Wi-Fi monitoring systems that typically rely on a full sampling rate receiver (RX) to capture signals at full bandwidth for demod ... Full text Cite

Savannah: A Real-time Programmable mmWave Baseband Processing Framework

Conference ACM Mobicom 2024 Proceedings of the 30th International Conference on Mobile Computing and Networking · December 4, 2024 5G new radio (NR) frequency range 2 (FR2) in the millimeter-wave (mmWave) band has a much shorter baseband processing deadline compared to that in the sub-7 GHz FR1 band. This tight deadline requires an efficient real-time system for baseband processing us ... Full text Cite

Federated Black-box Prompt Tuning System for Large Language Models on the Edge

Conference ACM Mobicom 2024 Proceedings of the 30th International Conference on Mobile Computing and Networking · December 4, 2024 Federated learning (FL) offers a privacy-preserving way to train models across decentralized data. However, fine-tuning pre-trained language models (PLMs) in FL is challenging due to restricted model parameter access, high computational demands, and commun ... Full text Cite

Savannah: Efficient mmWave Baseband Processing with Minimal and Heterogeneous Resources

Conference ACM Mobicom 2024 Proceedings of the 30th International Conference on Mobile Computing and Networking · December 4, 2024 5G new radio (NR) employs frequency range 2 (FR2) in the millimeter-wave (mmWave) bands, which employs a much shorter slot duration compared to FR1 (sub-7 GHz) systems and, therefore, poses significant challenges for softwarized baseband processing in virt ... Full text Cite

Full-Duplex Receiver With Wideband, High-Power RF Self-Interference Cancellation Based on Capacitor Stacking in Switched-Capacitor Delay Lines

Journal Article IEEE Journal of Solid State Circuits · July 1, 2024 The self-interference (SI) channels in full-duplex (FD) radios have large nano-second-scale delay spreads, which poses a significant challenge in designing SI cancelers that can emulate the SI channel over wide bandwidths. Passive implementations of high d ... Full text Cite

Field Trial of Coexistence and Simultaneous Switching of Real-Time Fiber Sensing and Coherent 400 GbE in a Dense Urban Environment

Journal Article Journal of Lightwave Technology · February 15, 2024 Recent advances in optical fiber sensing have enabled telecom network operators to monitor their fiber infrastructure while generating new revenue in various application scenarios including data center interconnect, public safety, smart cities, and seismic ... Full text Cite

Fast WDM provisioning with minimal probing: the first field experiments for DC exchanges

Journal Article Journal of Optical Communications and Networking · February 1, 2024 There are increasing requirements for data center interconnection (DCI) services, which use fiber to connect any DC distributed in a metro area and quickly establish high-capacity optical paths between cloud services and mobile edge computing and the users ... Full text Cite

Doubling Down on Wireless Capacity: A Review of Integrated Circuits, Systems, and Networks for Full Duplex

Journal Article Proceedings of the IEEE · January 1, 2024 The relentless demand for data in our society has driven the continuous evolution of wireless technologies to enhance network capacity. While current deployments of 5G have made strides in this direction using massive multiple-input–multiple-output (MIMO) ... Full text Cite

Semi-automatic line-system provisioning with an integrated physical-parameter-aware methodology: field verification and operational feasibility

Journal Article Journal of Optical Communications and Networking · January 1, 2024 We propose methods and an architecture to conduct measurements and optimize newly installed optical fiber line systems semi-automatically using integrated physics-aware technologies in a data center interconnection (DCI) transmission scenario. We demonstra ... Full text Cite

Swirls: Sniffing Wi-Fi Using Radios with Low Sampling Rates

Conference Proceedings of the International Symposium on Mobile Ad Hoc Networking and Computing Mobihoc · October 23, 2023 Next-generation Wi-Fi systems embrace large signal bandwidth to achieve significantly improved data rates, while requiring efficient methods for network monitoring and spectrum sharing applications. A radio receiver (RX) operating at low sampling rates can ... Full text Cite

Optimizing Sectorized Wireless Networks: Model, Analysis, and Algorithm

Conference Proceedings of the International Symposium on Mobile Ad Hoc Networking and Computing Mobihoc · October 23, 2023 Future wireless networks need to support the increasing demands for high data rates and improved coverage. One promising solution is sectorization, where an infrastructure node (e.g., a base station) is equipped with multiple sectors employing directional ... Full text Cite

Programmable Millimeter-Wave MIMO Radios with Real-Time Baseband Processing

Conference ACM Wintech 2023 Proceedings of the 2023 17th ACM Workshop on Wireless Network Testbeds Experimental Evaluation and Characterization Part of Mobicom 2023 · October 2, 2023 Baseband processing is one of the most time-consuming and computationally expensive tasks in radio access networks (RANs), which is typically realized in dedicated hardware. The concept of virtualizing the RAN functions by moving their computation to edge ... Full text Cite

Open-access millimeter-wave software-defined radios in the PAWR COSMOS testbed: Design, deployment, and experimentation

Journal Article Computer Networks · October 1, 2023 While millimeter-wave (mmWave) wireless has recently gained tremendous attention with the transition to 5G, developing a broadly accessible experimental infrastructure will largely facilitate the research and allow the community to make significant progres ... Full text Cite

Open EDFA gain spectrum dataset and its applications in data-driven EDFA gain modeling

Journal Article Journal of Optical Communications and Networking · September 1, 2023 Optical networks satisfy high bandwidth and low latency requirements for telecommunication networks and data center interconnection. To improve network resource utilization, machine learning (ML) is used to accurately model optical amplifiers such as erbiu ... Full text Cite

Wideband Full-Duplex Phased Array with Joint Transmit and Receive Beamforming: Optimization and Rate Gains

Journal Article IEEE ACM Transactions on Networking · August 1, 2021 Full-duplex (FD) wireless and phased arrays are both promising techniques that can significantly improve data rates in future wireless networks. However, integrating FD with transmit (Tx) and receive (Rx) phased arrays is extremely challenging, due to the ... Full text Cite

Directional Measurements in Urban Street Canyons from Macro Rooftop Sites at 28 GHz for 90% Outdoor Coverage

Journal Article IEEE Transactions on Antennas and Propagation · June 1, 2021 Path gain and effective directional gain in azimuth in urban canyons from actual rooftop base station sites are characterized based on a massive data set of 3000 links on 12 streets in two cities, with over 21 million individual continuous-wave power measu ... Full text Cite

A Full-Duplex Receiver with True-Time-Delay Cancelers Based on Switched-Capacitor-Networks Operating beyond the Delay-Bandwidth Limit

Journal Article IEEE Journal of Solid State Circuits · May 1, 2021 Wideband self-interference cancellation (SIC) in full-duplex (FD) radios requires the achievement of large delays to accurately emulate the SI channel. However, compact, power-efficient, low-loss/noise/distortion nanosecond-scale delays are extremely chall ... Full text Cite

A Survey and Quantitative Evaluation of Integrated Circuit-Based Antenna Interfaces and Self-Interference Cancellers for Full-Duplex

Journal Article IEEE Open Journal of the Communications Society · January 1, 2021 Full-duplex (FD) wireless - simultaneous transmission and reception on the same frequency - is a promising technique that can significantly improve spectrum efficiency and reduce communication latency in future wireless networks. To enable FD operation, th ... Full text Cite

Multi-Watt, 1-GHz CMOS Circulator Based on Switched-Capacitor Clock Boosting

Journal Article IEEE Journal of Solid State Circuits · December 1, 2020 There has been significant recent progress in the implementation of integrated non-reciprocal components based on linear periodically time-varying (LPTV) circuits. Nevertheless, integrated circulators still require a leap forward in power handling, clock p ... Full text Cite

Hybrid Scheduling in Heterogeneous Half- And Full-Duplex Wireless Networks

Journal Article IEEE ACM Transactions on Networking · April 1, 2020 Full-duplex (FD) wireless is an attractive communication paradigm with high potential for improving network capacity and reducing delay in wireless networks. Despite significant progress on the physical layer development, the challenges associated with dev ... Full text Cite

Wideband Full-Duplex Wireless via Frequency-Domain Equalization: Design and Experimentation

Journal Article · December 3, 2018 Full-duplex (FD) wireless can significantly enhance spectrum efficiency but requires tremendous amount of self-interference (SI) cancellation. Recent advances in the RFIC community enabled wideband RF SI cancellation (SIC) in integrated circuits (ICs) via ... Link to item Cite

Hybrid Scheduling in Heterogeneous Half-and Full-Duplex Wireless Networks

Conference Proceedings IEEE INFOCOM · October 8, 2018 Full-duplex (FD) wireless is an attractive communication paradigm with high potential for improving network capacity and reducing delay in wireless networks. Despite significant progress on the physical layer development, the challenges associated with dev ... Full text Cite

Full duplex circulator-receiver phased array employing self-interference cancellation via beamforming

Conference Digest of Papers IEEE Radio Frequency Integrated Circuits Symposium · August 7, 2018 In this paper, we show how phased-array beamforming can be synergistically combined with full-duplex (FD) to achieve wideband RF self-interference (SI) suppression with minimal link budget (transmitter (TX) and receiver (RX) array gain) penalty and with no ... Full text Cite

Demo abstract: Open-access full-duplex wireless in the ORBIT testbed

Conference INFOCOM 2018 IEEE Conference on Computer Communications Workshops · July 6, 2018 In order to support experimentation with full-duplex (FD) wireless, we integrated an open-access FD transceiver with the ORBIT testbed [1]. In particular, an ORBIT node with a National Instruments (NI)/Ettus Research Universal Software Radio Peripheral (US ... Full text Cite

Maximizing Broadcast Throughput under Ultra-Low-Power Constraints

Journal Article IEEE ACM Transactions on Networking · April 1, 2018 Wireless object-tracking applications are gaining popularity and will soon utilize emerging ultra-low-power device-to-device communication. However, severe energy constraints require much more careful accounting of energy usage than what prior art provides ... Full text Cite

Open-Access Full-Duplex Wireless in the ORBIT Testbed

Journal Article · January 9, 2018 In order to support experimentation with full-duplex (FD) wireless, we recently integrated an open-access FD transceiver in the ORBIT testbed. In this report, we present the design and implementation of the FD transceiver and interfaces, and provide exampl ... Link to item Cite

Demo abstract: Full-duplex with a compact frequency domain equalization-based RF canceller

Conference 2017 IEEE Conference on Computer Communications Workshops INFOCOM Wkshps 2017 · November 20, 2017 This demonstration presents a practical real-time full-duplex wireless link consisting of two full-duplex transceivers. Our prototyped full-duplex transceiver contains a custom-designed RF self-interference canceller and a National Instruments (NI) Univers ... Full text Cite

Performance Evaluation of Energy-Constrained Broadcast (EconCast) in Wireless Networks

Conference 2017 IEEE Wireless Communications and Networking Conference Workshops Wcncw 2017 · May 3, 2017 Wireless object tracking applications are gaining popularity and will soon utilize emerging ultra-low-power device-to-device communication. However, severe energy constraints require much more careful accounting of energy usage than what prior art provides ... Full text Cite

Full-duplex in a hand-held device - From fundamental physics to complex integrated circuits, systems and networks: An overview of the Columbia FlexICoN project

Conference Conference Record Asilomar Conference on Signals Systems and Computers · March 1, 2017 Full-duplex wireless is an exciting emerging wireless communication paradigm that also poses tremendous challenges at virtually every layer: from the antenna interface and integrated circuits (ICs) and systems to the network layer. This paper covers recent ... Full text Cite

Integrated full duplex radios

Journal Article IEEE Communications Magazine · January 1, 2017 Full duplex wireless has drawn significant interest in the recent past due to the potential for doubling network capacity in the physical layer and offering numerous other benefits at higher layers. However, the implementation of integrated full duplex rad ... Full text Cite

Maximizing broadcast throughput under ultra-low-power constraints

Conference Conext 2016 Proceedings of the 12th International Conference on Emerging Networking Experiments and Technologies · December 6, 2016 Wireless object tracking applications are gaining popularity and will soon utilize emerging ultra-low-power deviceto- device communication. However, severe energy constraints require much more careful accounting of energy usage than what prior art provides ... Full text Cite

Panda: Neighbor Discovery on a Power Harvesting Budget

Journal Article IEEE Journal on Selected Areas in Communications · December 1, 2016 Object tracking applications are gaining popularity and will soon utilize energy harvesting (EH) low-power nodes that will consume power mostly for neighbor discovery (ND) (i.e., identifying nodes within communication range). Although ND protocols were dev ... Full text Cite

Demo Abstract: Power-Aware neighbor discovery for energy harvesting things

Conference Proceedings of the 14th ACM Conference on Embedded Networked Sensor Systems Sensys 2016 · November 14, 2016 Object tracking applications are gaining popularity and will soon utilize energy harvesting low-power wireless nodes where power is mostly consumed for neighbor discovery. Such applications require the design and experimentation with low-power neighbor dis ... Full text Cite

Full-duplex wireless: Algorithms and rate improvement bounds for integrated circuit implementations

Conference Proceedings of the Annual International Conference on Mobile Computing and Networking MOBICOM · October 3, 2016 Full-duplex (FD) communication can substantially improve spectrum efficiency in wireless networks. Designing higher layer algorithms (e.g., for power control and scheduling) tailored for FD requires taking into account the special characteristics of the ph ... Full text Cite

Panda: Neighbor discovery on a power harvesting budget

Conference Proceedings IEEE INFOCOM · July 27, 2016 Object tracking applications are gaining popularity and will soon utilize Energy Harvesting (EH) low-power nodes that will consume power mostly for Neighbor Discovery (ND) (i.e., identifying nodes within communication range). Although ND protocols were dev ... Full text Cite

Demo: Full-Duplex Wireless based on a Small-Form-Factor Analog Self-Interference Canceller

Conference Proceedings of the International Symposium on Mobile Ad Hoc Networking and Computing Mobihoc · July 5, 2016 A demonstration of a real-time full-duplex wireless link is presented, in which a pair of full-duplex transceivers perform simultaneous transmission and reception on the same frequency channel. A full-duplex transceiver is composed of a custom-designed sma ... Full text Cite

Outage Minimization for a Fading Wireless Link with Energy Harvesting Transmitter and Receiver

Journal Article IEEE Journal on Selected Areas in Communications · March 1, 2015 This paper studies online power control policies for outage minimization in a fading wireless link with energy harvesting transmitter and receiver. The outage occurs when either the transmitter or the receiver does not have enough energy, or the channel is ... Full text Cite

Power control policies for a wireless link with energy harvesting transmitter and receiver

Conference 2014 12th International Symposium on Modeling and Optimization in Mobile Ad Hoc and Wireless Networks Wiopt 2014 · January 1, 2014 This paper addresses the outage minimization problem for a wireless link where both the transmitter and the receiver are powered by harvested energy, and the energy arrival processes of both nodes are correlated. We propose three power control policies to ... Full text Cite