基于差分进化的非规则LDPC码优化设

为优化非规则低密度奇偶校验(LDPC)码的度分布，引入差分进化(DE)极值搜索算法，根据差分进化后的最佳成员矢量，确定非规则LDPC码变量点的度分布。基于期望码率和变量点的度分布调整校验点的度分布，获得期望码率下的LDPC码。为提高优化搜索效率，改进差分进化停止准则，从而有效控制进化迭代次数。在此基础上，设计一组加性高斯白噪声(AWGN)信道下的非规则LDPC码。实验结果表明，该方法的译码复杂度低，设计的LDPC码具有较高的噪声门限。

Optimal Design of Irregular LDPC Code Based on Differential Evolution

To optimize the degree distributions of irregular Low-density Parity-check（LDPC） codes,a search algorithm of extreme value based on differential evolution is introduced.The variables＇ degree distributions of the LDPC code are determined by using the best member vectors,the check nodes＇ degree distribution is adjusted according to both the expected rate and the variable nodes＇ degree distribution,and the LDPC codes under the expected rate are designed.To get more efficient controlling on the iteration number,the evolution stop criterion is modified.A group of irregular LDPC codes under AWGN channel are designed.Experimental results show that this method has low decoding complexity,and LDPC code has the high noise threshold.