Universality for the noisy Slepian-Wolf problem via spatial coupling

Conference Paper

We consider a noisy Slepian-Wolf problem where two correlated sources are separately encoded and transmitted over two independent binary memoryless symmetric channels. Each channel capacity is assumed to be characterized by a single parameter which is not known at the transmitter. The receiver has knowledge of both the source correlation and the channel parameters. We call a system universal if it retains near-capacity performance without channel knowledge at the transmitter. Kudekar et al. recently showed that terminated low-density parity-check (LDPC) convolutional codes (a.k.a. spatially-coupled LDPC ensembles) can have belief-propagation thresholds that approach their maximum a-posteriori thresholds. This was proven for binary erasure channels and shown empirically for binary memoryless symmetric channels. They also conjectured that the principle of spatial coupling is very general and the phenomenon of threshold saturation applies to a very broad class of graphical models. In this work, we derive an area theorem for the joint decoder and empirically show that threshold saturation occurs for this problem. As a result, we demonstrate near-universal performance for this problem using the proposed spatially-coupled coding system. A similar result is also discussed briefly for the 2-user multiple-access channel. © 2011 IEEE.

Full Text

Duke Authors

Cited Authors

  • Yedla, A; Pfister, HD; Narayanan, KR

Published Date

  • October 26, 2011

Published In

  • Ieee International Symposium on Information Theory Proceedings

Start / End Page

  • 2567 - 2571

International Standard Book Number 13 (ISBN-13)

  • 9781457705953

Digital Object Identifier (DOI)

  • 10.1109/ISIT.2011.6034032

Citation Source

  • Scopus