基于平均概率和停止准则的多元LDPC码加权符号翻转译码算法

Weighted symbol-flipping decoding for non-binary LDPC codes based on average probability and stopping criterion

为了提高多元低密度奇偶校验（LDPC,low density parity-check）码符号翻转译码算法的性能并降低译码的复杂度,提出了基于平均概率和停止准则的多元LDPC码加权符号翻转译码（APSCWSF,average probability and stopping criterion weighted symbol flipping）算法。该算法将校验节点邻接符号节点的平均概率信息作为权重,使翻转函数更加有效,提高符号的翻转效率,进而改善译码性能。并且通过设置迭代停止准则进一步加快算法的收敛速度。仿真结果显示,在加性高斯白噪声信道下,误符号率为10-5时,相比WSF算法、NSCWSF算法（Osc=10）和NSCWSF算法（Osc=6）,APSCWSF算法（Osc=10）分别获得约0.68 d B、0.83 d B和0.96 d B的增益。同时,APSCWSF算法（Osc=6）的平均迭代次数也分别降低78.60%~79.32%、74.89%~75.95%和67.20%~70.80%。

In order to improve the decoding performance and reduce the decoding complexity of weighted symbols flip- ping decoding algorithm for nonbinary low density parity-check（LDPC） code, a weighted symbols flipping decoding for nonbinary LDPC codes based on average probability and stopping criterion was proposed. The algorithm puts the average probability of all the information nodes adjacent to the check node as weights to make the flipping-function more effec- tively and improve the efficiency of the flipping-symbols, and then improves the decoding performance. At the same time, the algorithm adds a stopping criterion controlling decoding iterations to further improve the decoding speed. Simulation results show that compared to WSF algorithm, NSCWSF algorithm（Osc=lO） and NSCWSF algorithm（Osc=6）, the new algorithm proposed（Osc=10） is gotten about 0.68 dB, 0.83 dB and 0.96 dB gain at the symbol error rate of 10^-5 in the presence of additive white Gaussian noise（AWGN）, meanwhile, the average number of decoding iterations is also re- duced by 78.60%-79.32%, 74.89%-75.95% and 67.2%-70.8%, respectively.