Least reliable messages based early termination method for LT soft decoder

TL;DR

This paper introduces a new early termination method for LT decoders that reduces computational complexity and decoding iterations by monitoring sign changes in message clusters, applicable to various BP-decodable codes.

Contribution

The paper presents the least reliable messages (LRM) early termination method, which improves efficiency without performance loss in BP-based decoders.

Findings

Significant reduction in decoding iterations.

Lower computational complexity in early termination.

Applicable to multiple BP-decodable code families.

Abstract

In this paper, we propose a new early termination method (ETM) for Luby transform (LT) belief propagation (BP) decoder. The proposed ETM, which we call least reliable messages (LRM), observes only sign alterations of a small cluster in log-likelihood ratio (LLR) messages passing between nodes in BP decoder. Simulation results and complexity analyzes show that LRM significantly lower computational complexity of early termination section in decoder without any performance degradation and decreases the average decoding iteration amounts compared to conventional ETMs in literature. The method can be easily applied to code families which can be decoded by BP such as low density parity check (LDPC) codes, polar codes and Raptor codes.