Math @ Duke

Publications [#319355] of Henry Pfister
Papers Published
 Yedla, A; Nguyen, PS; Pfister, HD; Narayanan, KR, Universal codes for the Gaussian MAC via spatial coupling,
2011 49th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2011
(December, 2011),
pp. 18011808, ISBN 9781457718168 [doi]
(last updated on 2018/10/19)
Abstract: We consider transmission of two independent and separately encoded sources over a twouser binaryinput Gaussian multipleaccess channel. The channel gains are assumed to be unknown at the transmitter and the goal is to design an encoderdecoder pair that achieves reliable communication for all channel gains where this is theoretically possible. We call such a system universal with respect to the channel gains. Kudekar et al. recently showed that terminated lowdensity paritycheck convolutional codes (a.k.a. spatiallycoupled lowdensity paritycheck ensembles) have beliefpropagation thresholds that approach their maximum aposteriori thresholds. This was proven for binary erasure channels and shown empirically for binary memoryless symmetric channels. It was 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 nearuniversal performance for this problem using the proposed spatiallycoupled coding system. © 2011 IEEE.


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