LDPC码的双决策残差值置信度传播译码算法

Double decision residual confidence propagation decoding algorithm for LDPC code

关键词:  信道编码  低密度奇偶校验码  译码算法  残差值  动态调度

Key words:  channel coding  low-density parity-check(LDPC)  decoding algorithm  residual  dynamic scheduling

摘要:

针对低密度奇偶校验（low-density parity-check,LDPC）码的多种动态调度残差值置信度传播（residual belief propagation,RBP）译码算法存在贪婪性和静默变量节点的问题,引入校验方程和概率残差值共同决策的方法,提出双决策残差值置信度传播译码算法（double decision RBP,DD-RBP）。首先根据计算的概率残差值选择需要更新的变量节点,以减少静默变量节点的个数。然后根据校验方程结果更新相关校验节点对应边的残差值,进一步降低贪婪性。最后结合更新后的残差值,在需要更新的变量节点所连接边的集合中,局部或全局选择残差值最大的边并更新,重复上述过程直至达到设置的最大次数。理论分析与仿真结果表明:对于IEEE802.16e标准和5G NR标准下的低密度奇偶校验码,所提出的双决策残差值置信度传播译码算法通过增加复杂度,在加性高斯白噪声信道和瑞利衰落信道下的译码性能优于其他译码算法。

Abstract:

In order to solve the problems of greediness and silent variable nodes in multiple dynamic scheduling residual belief propagation (RBP) decoding algorithms for low-density parity-check (LDPC) codes, a double decision residual belief propagation decoding algorithm (DD-RBP) is proposed by introducing the method of joint decision based on the check equation and probability residual value. Firstly, the variable nodes that need to be updated are selected according to the calculated probability residual value, which can reduce the number of silent variable nodes. Then, according to the results of the check equation, the residual values of the corresponding edges of the relevant check nodes are updated to further reduce the greediness. Finally, combined with the updated residual value, in the set of edges connected by the variable nodes that need to be updated, the edge with the largest residual value is selected locally or globally and updated, and the above process is repeated until the maximum number of settings is reached. Theoretical and simulation analyses demonstrate that, for low-density parity-check codes under IEEE802.16e standard and 5G NR standard, the proposed double decision residual belief propagation decoding algorithm performs better than other algorithms in decoding under additive Gaussian white noise channels and Rayleigh fading channels with increased complexity.