Reliability-based iterative decoding of LDPC codes using likelihood accumulation

In this work, we present an improvement on low complexity serial concatenation of belief propagation (BP) order statistic decoding (OSD) algorithm for low-density parity-check (LDPC) codes. We introduce a more reliable method to reconstruct ordered information sequence in terms of the accumulated log-likelihood ratio (LLR) transitions of variable nodes. We give a general expression for both the existing BPOSD algorithm and our proposed, new method according to a structure similar to an infinite impulse response (IIR) filter. This improved algorithm achieves noticeable performance gains with only modest increase in computation complexity.