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Book ChapterDOI

An algebraic description of iterative decoding schemes

TLDR
It is explained exactly how suboptimal algorithms approximate the optimal, and it is shown how good these approximations are in some special cases.
Abstract
Several popular, suboptimal algorithms for bit decoding of binary block codes such as turbo decoding, threshold decoding, and message passing for LDPC, were developed almost as a common sense approach to decoding of some specially designed codes After their introduction, these algorithms have been studied by mathematical tools pertinent more to computer science than the conventional algebraic coding theory We give an algebraic description of the optimal and suboptimal bit decoders and of the optimal and suboptimal message passing We explain exactly how suboptimal algorithms approximate the optimal, and show how good these approximations are in some special cases

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Citations
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Book

Information Theory, Inference and Learning Algorithms

TL;DR: A fun and exciting textbook on the mathematics underpinning the most dynamic areas of modern science and engineering.
Journal ArticleDOI

Constructing free-energy approximations and generalized belief propagation algorithms

TL;DR: This work explains how to obtain region-based free energy approximations that improve the Bethe approximation, and corresponding generalized belief propagation (GBP) algorithms, and describes empirical results showing that GBP can significantly outperform BP.
Journal ArticleDOI

Decoding of High Rate Convolutional Codes Using the Dual Trellis

TL;DR: This paper deals with a posteriori probability (APP) decoding of high-rate convolutional codes, using the dual code's trellis, and efficient techniques for normalization and extrinsic log-likelihood ratio (LLR) calculation are presented which reduce implementation complexity significantly.
Journal ArticleDOI

LDPC codes: a group algebra formulation

TL;DR: An entirely new approach to iterative decoding of low-density parity-check codes is proposed, which gives new insights into the issues of iterative decode from the algebraic coding theorist's point of view.
Journal ArticleDOI

Bit-optimal decoding of codes whose Tanner graphs are trees

TL;DR: A group algebra formulation for bit-optimal decoding of binary block codes is introduced to give a simple algebraic proof that Pearl's and Gallager's belief propagation decoding algorithms are bit-Optimal when the Tanner graph of the code is a tree.
References
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Book

Low-Density Parity-Check Codes

TL;DR: A simple but nonoptimum decoding scheme operating directly from the channel a posteriori probabilities is described and the probability of error using this decoder on a binary symmetric channel is shown to decrease at least exponentially with a root of the block length.
Proceedings ArticleDOI

Near Shannon limit error-correcting coding and decoding: Turbo-codes. 1

TL;DR: In this article, a new class of convolutional codes called turbo-codes, whose performances in terms of bit error rate (BER) are close to the Shannon limit, is discussed.
Journal ArticleDOI

Iterative decoding of binary block and convolutional codes

TL;DR: Using log-likelihood algebra, it is shown that any decoder can be used which accepts soft inputs-including a priori values-and delivers soft outputs that can be split into three terms: the soft channel and aPriori inputs, and the extrinsic value.

Near Shannon limit error-correcting coding and decoding

Claude Berrou
TL;DR: A new class of convolutional codes called turbo-codes, whose performances in terms of bit error rate (BER) are close to the Shannon limit, is discussed.