Check Reliability Based Bit-Flipping Decoding Algorithms for LDPC Codes

TL;DR

This paper proposes new reliability-based bit-flipping decoding algorithms for LDPC codes, improving performance and reducing complexity by incorporating check node reliability into the decoding process.

Contribution

Introduction of novel reliability definitions and BF algorithms that consider check node reliability, enhancing decoding performance for LDPC codes.

Findings

Hard-decision BF with check node reliability outperforms conventional BF.

Soft-decision BF with check node reliability surpasses traditional SD BF decoders.

SD version achieves performance comparable to or better than SPA with lower complexity.

Abstract

We introduce new reliability definitions for bit and check nodes. Maximizing global reliability, which is the sum reliability of all bit nodes, is shown to be equivalent to minimizing a decoding metric which is closely related to the maximum likelihood decoding metric. We then propose novel bit-flipping (BF) decoding algorithms that take into account the check node reliability. Both hard-decision (HD) and soft-decision (SD) versions are considered. The former performs better than the conventional BF algorithm and, in most cases, suffers less than 1 dB performance loss when compared with some well known SD BF decoders. For one particular code it even outperforms those SD BF decoders. The performance of the SD version is superior to that of SD BF decoders and is comparable to or even better than that of the sum-product algorithm (SPA). The latter is achieved with a complexity much less than that required by the SPA.