基于联合判决消息传递机制的LDPC码译码算法研究

采用消息传递算法(Message passing algorithm)对LDPC码进行译码时,变量消息的振荡会引起错误的发生.本文以(600.300)非规则LDPC码仿真实验为例分析了不同译码效果下判决消息均值的分布特点,并结合环的特点,分析了译码产生错误判决的原因.研究了"纠删"型消息传递机制和联合判决迭代停止准则,针对判决消息出现振荡情况,提出以"纠删"方式处理变量消息的更新,并结合变量节点判决消息均值分布趋势与伴随式结果确定迭代终止条件.在此基础上,提出一种新的LDPC码译码算法.仿真分析表明,新的译码算法能够在减少迭代次数和降低译码复杂度的同时,有效提高译码的纠错性能.

A Decoding Algorithm Based on Joint judging message passing schedule for Low-Density Parity Check Codes

For message passing algorithm for LDPC codes decoding,the oscillation of variable message will aroge error.The paper has summarized the characteristics about the mean of jRaSing message under different decoding results.Considering the characteristic of cvcle.the essential reason for wrong decision has been analysed.Based on the research for correcting-erase schedule and joint judging iteration stopping criterion,a new decoding algorithm for LDPC codes is presented.For the oscillatory variable message,the correcting-erase schedule will be adopted in updating message,and the condition for stopping iteration should be codetennined by the distribution of mean of judging message and syndrome.The simulation results show that the new algorithm could reduce the number of iterationand complexity of decoding,and it could also improve the correcting performance.