低密度奇偶校验码译码算法及其性能仿真研究

摘要

低密度奇偶校验码（LDPC码）译码主要包括基于硬判决和基于软判决的译码。文章对这两种译码方法中的典型算法（BF算法和BP算法）和一种改进的对数域算法（APP-LLR算法）进行了仿真研究；比较并分析了信噪比、码长和迭代次数等参数对译码性能影响。仿真结果表明误码率会随着码长和迭代次数的增加而减小，同时在同等条件下软判决译码算法的误码性能比硬判决优越。%Low-Density Parity-Check codes (LDPC codes) decoding is mainly based on hard decision and soft decision. Two kinds of typical algorithm in decoding method (BF algorithm and BP algorithm) and an improved log-domain algorithm (APP-LLR algorithm) have been researched and simulated;compare and analysis the SNR,code length and the number of iterations impact on decoding performance. The simulation results show that the error rate will decrease with the increase of the code length and the number of iterations, and the ber (bit erro rate)performance of soft decision decoding algorithm is superior to hard decision under the same condition.