一种低复杂度的多元LDPC译码算法

A Low Complexity Decoding Algorithm for Nonbinary LDPC Codes

针对多元低密度奇偶校验(LDPC)码译码复杂度高、时延大等问题,提出了一种基于硬信息的低复杂度多元LDPC译码算法。来自信道的接收信号在初始化时,先进行非均匀量化预处理。在迭代过程中,校验节点端只需传输单个比特的二进制硬可靠度信息至变量节点。在变量节点端,可靠度信息按比特位进行简单的累加和更新,无需任何的系数修正操作。同时,变量节点使用了全信息的方式将信息传输至与其相邻的校验节点。仿真结果显示,与基于比特可靠度(BRB)的多元LDPC译码算法相比,提出的算法在较低量化比特情况下,能获得约0.3 d B的译码性能增益,且译码复杂度更低。

For the large decoding complexity and high latency in nonbinary low density parity check （ LD-PC） decoding,a low complexity decoding algorithm based on hard-information for nonbinary LDPC codes is presented in this paper. The received signals from the channel are quantized with a non-uniform quanti-zation scheme. During the decoding procedure,binary hard reliability information is transmitted from check nodes to variable nodes. At variable nodes,the reliability messages are accumulated and updated bit-by-bit without any scaling operations. Furthermore,full messages rather than extrinsic messages are employed at the variable nodes to pass back the information. Simulation results show that,compared with the bit-reli-ability based（BRB） algorithm,the presented algorithm can achieve about 0.3 dB performance gain with low quantization bits and lower decoding complexity.