AWGN信道下LDPC码的译码算法研究

Study on Decoding Algorithm for LDPC Codes under AWGN Channel

在高斯白噪声(AWGN)信道情况下,针对LDPC码的译码算法进行深入分析后,对适用于低密度奇偶校验(LDPC)码的硬判决译码算法与软判决译码算法进行了仿真与对比分析,并通过引入乘性校正因子以降低软判决算法中对数域置信传播(LLR-BP)算法的变量消息相关性。仿真分析表明改进后的LLR-BP算法与原算法相比,在几乎不增加计算复杂度的情况下,其译码纠错性能得到了明显的改善。因而改进后的LLR-BP算法具有明显的优越性。

Under the condition of the Additive White Gaussian Noise （AWGN） channel, both the hard and soft decision decoding algorithms suitable for LDPC codes are simulated and comparatively analyzed based on analyzing the decoding algorithm for LDPC codes. The variable message correlation for Log-Likelihood-Rati0 Belief-Propagation （LLR-BP） aigorithm in soft decision algorithm is：decreased by introducing a multip!icative correction factor. The simulation results show that the decoding error-correction performance of the modified LLR-BP algorithm is greatly improved with little increase of computing complexity.