基于软译码的系统LT码及其无线信道应用

LT码在删除信道下显示出优异的纠删性能,但在无线信道中由于信道噪声固有的影响,接收端必然产生误码,错误的译码起始信息导致LT码在解码后出现错误传播现象。为了减少误码,实现LT码在无线信道下的应用,提出构造系统LT码,同时在译码时产生校验矩阵,采用基于对数似然比的置信传播算法(LLR-BP)进行软信息译码的方法。仿真实验结果表明,基于软译码的系统LT码具备良好的纠错性能,显示了其在无线信道应用的可行性和有效性。

Soft Decoding of Systematic LT-codes and Application in Wireless Channel

Luby Transform codes(LT) performs well over Binary Erasure Channel (BEC), but as the existence of noise innate in wireless channel, some error codes can be generated at the receiver, these error codes result in error propagation when they are decoded as the initial decoding information. For the sake of reducing these error codes and achieve credible transmission over wireless channel, we propose the soft decoding of systematic LT-codes, at the receiver, we generate parity check matrix and apply belief propagation algorithm based on logarithm likelihood ratio (LLR-BP) to decode. Experiment results show that the systematic LT-codes based on soft decoding possess excellent error correction capability, and demonstrate the feasibility and availability of applying systematic LT codes over wireless channel.