Threshold saturation of spatially coupled sparse superposition codes for all memoryless channels
Threshold saturation of spatially coupled sparse superposition codes for all memoryless channels
复制标题
所有无记忆通道的空间耦合稀疏叠加码的阈值饱和
DOI:
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发表时间:
2016
期刊:
影响因子:
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通讯作者:
N. Macris
中科院分区:
文献类型:
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作者:
Jean Barbier;M. Dia;N. Macris
We recently proved threshold saturation for spatially coupled sparse superposition codes on the additive white Gaussian noise channel [1]. Here we generalize our analysis to a much broader setting. We show for any memoryless channel that spatial coupling allows generalized approximate message-passing (GAMP) decoding to reach the potential (or Bayes optimal) threshold of the code ensemble. Moreover in the large input alphabet size limit: i) the GAMP algorithmic threshold of the underlying (or uncoupled) code ensemble is simply expressed as a Fisher information; ii) the potential threshold tends to Shannon's capacity. Although we focus on coding for sake of coherence with our previous results, the framework and methods are very general and hold for a wide class of generalized estimation problems with random linear mixing.