基于分布式奇偶校验码的低复杂度极化码SCLF译码算法

Low-Complexity SCLF Decoding Algorithm for Polar Codes Based on Distributed Parity Check Codes

摘要:

针对极化码串行抵消列表比特翻转(Successive Cancellation List Bit-Flip, SCLF)译码算法复杂度较高的问题,提出一种基于分布式奇偶校验码的低复杂度极化码SCLF译码(SCLF Decoding Algorithm for Low-Complexity Polar Codes Based on Distributed Parity Check Codes,DPC-SCLF) 算法。与仅采用循环冗余校验(Cyclic Redundancy Check,CRC)码校验的SCLF译码算法不同,该算法首先利用极化信道偏序关系构造关键集,然后采用分布式奇偶校验(Parity Check,PC)码与CRC码结合的方式对错误比特进行检验、识别和翻转,提高了翻转精度,减少了重译码次数。此外,在译码时利用路径剪枝操作,提高了正确路径的竞争力,改善了误码性能,且利用提前终止译码进程操作,减少了译码比特数。仿真结果表明,与D-Post-SCLF译码算法和RCS-SCLF译码算法相比,所提出算法具有更低的译码复杂度且在中高信噪比下具有更好的误码性能。

Abstract:

Aiming at the problem of high complexity of successive cancellation list bit-flip (SCLF) decoding algorithm, a SCLF decoding algorithm for low-complexity polar codes based on distributed parity check codes (DPC-SCLF algorithm) is proposed. Different from the SCLF decoding algorithm which only uses CRC codes verification, the proposed algorithm first constructs the critical set by using the polar channel partial order relationship, and then uses the combination of distributed parity check codes and CRC codes to check, identify and flip the error bits, so the flipping accuracy is improved and the number of the redecoding is reduced. In addition, the path pruning operation during decoding is used to improve the competitiveness of the correct path and the performance of the bit error ratio (BER), and the number of decoding bits is reduced by using the early termination decoding process operations. The simulation results show that compared with the D-Post-SCLF algorithm and RCS-SCLF decoding algorithm, the proposed algorithm has the lower decoding complexity and the better performance of the BER under the medium and high signal-to-noise ratio.