@inproceedings{f51befaaea374f78baf56f2fea299f61,
title = "Channel dispersion and moderate deviations limits for memoryless channels",
abstract = "Recently, Altug and Wagner [1] posed a question regarding the optimal behavior of the probability of error when channel coding rate converges to the capacity sufficiently slowly. They gave a sufficient condition for the discrete memoryless channel (DMC) to satisfy a moderate deviation property (MDP) with the constant equal to the channel dispersion. Their sufficient condition excludes some practically interesting channels, such as the binary erasure channel and the Z-channel. We extend their result in two directions. First, we show that a DMC satisfies MDP if and only if its channel dispersion is nonzero. Second, we prove that the AWGN channel also satisfies MDP with a constant equal to the channel dispersion. While the methods used by Altug and Wagner are based on the method of types and other DMC-specific ideas, our proofs (in both achievability and converse parts) rely on the tools from our recent work [2] on finite-blocklength regime that are equally applicable to non-discrete channels and channels with memory.",
keywords = "AWGN channel, Channel capacity, Channel dispersion, Discrete channels, Finite blocklength regime, Moderate deviations, Shannon theory",
author = "Yury Polyanskiy and Sergio Verd{\'u}",
year = "2010",
doi = "10.1109/ALLERTON.2010.5707068",
language = "English (US)",
isbn = "9781424482146",
series = "2010 48th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2010",
pages = "1334--1339",
booktitle = "2010 48th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2010",
note = "48th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2010 ; Conference date: 29-09-2010 Through 01-10-2010",
}