An improved implementation of sum-product algorithm for LDPC decoder

Abstract

An improved decoding algorithm for low-density parity-check (LDPC) codes is presented. By taking advantages of the first-term Taylor's series multiple expansion to approximate the correction term of the Jacobian logarithm used in LLR-SPA (log-likelihood ratio sum-product algorithm), we propose an algorithm which significantly simplifies the check node update computation of the optimal LLR-SPA. Besides, the parameter δ is introduced to determine suitable expansion points. The simulation result shows that the proposed method with ten expansion points when δ is set to 0.01 has almost identical performance compared with ideal SPA algorithm and outperforms both the min-sum algorithm (MS), the offset min-sum algorithm (OMS) and the normalised min-sum algorithm (NMS). The architecture of proposed method is also presented for implementation, which has reduced computational complexity and is feasible for hardware implementation.

Certain investigations on recent advances in the design of decoding algorithms using low‐density parity‐check codes and its applications

“…The recent studies indicate a few outstanding research works regarding SPA which can achieve better decoding stability without exhibiting the inherent data dependency issues 78 . However, regarding SPA issues, there exist several gaps or limitations which still remains unexplored 79 …”