融合路径度量值和行重特性的Polar码SCL译码算法

SCL Decoding Algorithm for Polar Code Combined with Path Metric and Row Weight Property

首先提出基于初始对数似然比(Log-Likelihood Ratio,LR)与路径度量值(Path Metric,PM)的PM-LLR-SCL译码算法,在接收端初始LLR和PM值之间建立映射关系,并通过重排PM值完成翻转功能。其次,提出基于极化码生成矩阵的行重特性和PM值的PM-RW-SCL译码算法,不仅考虑了Polar码的最小码距和极化子信道可靠度,同时将路径分裂每一层的PM值引入到译码策略中,从而提高了译码性能。仿真结果显示,与串行抵消列表比特翻转(Successive Cancellation List Bit-flip,SCLF)相比,提出的PM-LLR-SCL算法最大可获得约0.23 dB的性能增益,而基于路径数量的复杂度降低了约62%;与基于行权重的串行抵消列表翻转译码算法相比,PM-RW-SCL算法最大可获得约1.5 dB的性能增益,而复杂度降低了约39%。

A Successive Cancellation List(SCL)decoding algorithm for Polar code based on initial Log-Likelihood Ratio(LLR)and Path Metric(PM),called PM-LLR-SCL,is presented.For the presented algorithm,the mapping relationship between LLR and PM is constructed.Then the flipping operation is replaced by the PM re-arrangement.Second,an SCL decoding algorithm based on the row-weight property of the generator matric and the PM,called PM-RW-SCL is further presented.The presented PM-RW-SCL algorithm not only considers the minimum-distance of the Polar code and the reliability of the sub-channel,but also introduces the PM into the decoding strategy so as to improve the decoding performance.Simulation results show that,compared with the SCL Bit-flip(SCLF),the presented PM-LLR-SCL algorithm can achieve about 0.23 dB performance gain at the most,while the complexity can be reduce by about 62%.Similarly,compared with the SCLF based on row weight,the presented PM-RW-SCL algorithm can achieve about 1.5 dB gain at the most,while the complexity can be reduce by about 39%.