Sign alterations of LLR values based early termination method for LT BP decoder

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.

Performance Analysis of LT Codec Architecture Using Different Processor Templates

“…In LT decoder, sign of loglikelihood ratio (LLR) is used in belief propagation (BP) decoder structure. C. Albayrak et al proposes a method that has less computational complexity in terms of iterations for decoding LT encoded signal [14]. J.…”