Title
Local-Optimality Guarantees Based on Paths for Optimal Decoding.
Abstract
This paper presents a unified analysis framework that captures recent advances in the study of local-optimality characterizations for codes on graphs. These local-optimality characterizations are based on combinatorial structures embedded in the Tanner graph of the code. Local optimality implies both unique maximum likelihood optimality and unique linear programming (LP) decoding optimality. Also, an iterative message-passing decoding algorithm is guaranteed to find the unique locally optimal codeword if one exists. We demonstrate an instance of this proof technique by considering a definition of local optimality that is based on the simplest combinatorial structures in Tanner graphs, namely, paths of length h. We apply the technique of local optimality to binary Tanner codes (including any low-density parity-check code, and in particular any irregular repeat-accumulate code with both even and odd repetition factors). Inverse polynomial bounds in the code length are proved on the word error probability of LP decoding for binary Tanner codes. When the local codes are restricted to single parity-check codes, these bounds also hold for decoding by a certain iterative message-passing decoding algorithm.
Year
DOI
Venue
2013
10.1137/120886674
SIAM JOURNAL ON DISCRETE MATHEMATICS
Keywords
Field
DocType
coding theory,Tanner codes,local optimality,maximum likelihood,linear programming decoding,error probability,iterative message-passing decoding,repeat-accumulate codes
Discrete mathematics,Combinatorics,Concatenated error correction code,Sequential decoding,Coding theory,Code word,Linear code,Tanner graph,Decoding methods,List decoding,Mathematics
Journal
Volume
Issue
ISSN
27
4
0895-4801
Citations 
PageRank 
References 
0
0.34
10
Authors
2
Name
Order
Citations
PageRank
Guy Even11194136.90
Nissim Halabi283.58