一种基于新度量准则的极化码SCLF译码算法

A SCLF Decoding Algorithm of Polar Codes Based on New Measurement Criteria

摘要:

为了解决串行抵消(Successive Cancellation, SC)译码算法在中短码长情况下译码性能不佳的问题,在SC译码算法的基础上增加路径列表和比特翻转方法得到一种改进的串行抵消列表翻转(Successive Cancellation List Flip, SCLF)译码算法。该算法利用比特翻转构建最不可靠的信息位集合,称为翻转集合(Flipping Set, FS),同时提出一种新的度量法则来缩小FS的范围、提高FS的准确率。仿真结果表明,随着信噪比的增大,所提出的SCLF译码算法误块率(Block Error Rate, BLER)有较大提升,当BLER为10-3时,SCLF(码长N=256,列表大小L=8)译码算法的增益比SC(N=256)译码算法提升了0.55dB；当BLER为10-4时,SCLF(N=256,L=8)译码算法的增益比CA-SCL(N=256,L=8)译码算法提升了0.22dB；当BLER为10-5时,SCLF(N=256,L=16)译码算法的增益比CA-SCL(N=256,L=16)译码算法提升了0.17dB。

Abstract:

In order to solve the problem of the worse decoding performance of the successive cancellation (SC) decoding algorithm under the medium/short code lengths, an improved successive cancellation list flip (SCLF) decoding algorithm is proposed by adding the path list and bit-flipping method on the basis of the SC decoding algorithm. The algorithm uses the bit-flipping to build the most unreliable information bit sets called as the flipping set (FS), and a new measurement criterion is proposed to reduce the range of the FS and improve the accuracy of the FS. The simulation results show that the proposed SCLF decoding algorithm can greatly improve the block error rate (BLER) with the increase of the signal-to-noise ratio (SNR). The gain of the SCLF (N=256, L=8) decoding algorithm is 0.55dB higher than that of the SC (N=256) decoding algorithm at BLER=10-3, the gain of the SCLF (N=256, L=8) decoding algorithm is 0.22dB higher than that of the CA-SCL (N=256, L=8) decoding algorithm at BLER=10-4, and the gain of the SCLF (N=256, L=16) decoding algorithm is 0.17dB higher than that of the CA-SCL (N=256, L=16) decoding algorithm at BLER=10-5.