基于对数域的多进制LDPC码改进译码算法

摘要

为了进一步降低多进制LDPC码译码的复杂度,分析了扩展最小和算法(EMS)存在的不足,提出了一种基于对数域的多进制LDPC码的改进译码算法.该算法一方面根据每次迭代中变量节点的概率分布对的平均方差自适应选择FHT的阶数；另一方面算法中校验节点的更新运算由乘法转化为基于对数域上的加法运算,从而更易于硬件实现.仿真结果表明,与EMS算法相比,该算法性能与收敛速率均有明显改进.%To reduce the complexity of decoding algorithm for non-binary LDPC codes and overcome the drawback of the extended min-sum (EMS) algorithm, an improved EMS decoding algorithm based on logarithm domain is proposed. The algorithm adaptively chooses the rank of FHT in each iteration step according to the average variance of bit nodes' probability pairs. It translates the multiplication calculation for updating parity-check notes into addition calculation based on logarithm domain. It makes the hardware easier to realize. The simulation shows the proposed algorithm can achieve better performance and converge faster than EMS algorithm.