基于LDPC码校验节点度的分类修正最小和算法

Check node degree-based modified min-sum decoding algorithm with classification for LDPC codes

为了减小低密度奇偶校验(low-density parity-check,LDPC)码的译码算法复杂度,提高译码性能,该文针对致信传播(belief propagation,BP)译码算法及其简化算法的分析,提出了一种基于校验节点度的分类修正最小和译码算法。该算法将最小和译码算法中校验节点输入外信息绝对值的最小值和次小值分类,并根据该节点的度计算与BP算法的偏移量,分别选择不同的阈值和修正因子对外信息进行补偿。仿真结果表明,该算法在高信噪比区域的译码性能高于BP算法,并且计算复杂度大大低于BP算法,是一种适用于各种校验节点度分布,而且是能较好兼顾性能与实现复杂度的译码算法。

A check node degree-based modified min-sum algorithm which classifies the codes was developed to reduce the complexity and improve the performance of decoding algorithm for low-density parity-check （LDPC） codes. The algorithm corrects both the minimum and sub-minimum absolute values of incoming messages in the check nodes. Two correction factors are obtained by calculating the offset between the belief propagation （BP） algorithm and the rain-sum algorithm based on the check node degree. Simulations show that the algorithm achieves better performance than the BP algorithm at high signal noise ratio. The algorithm is also less complex than the BP algorithm and provides a good tradeoff between performance and complexity for any check node degree distribution in the LDPC codes.