北京邮电大学学报

  • EI核心期刊

北京邮电大学学报 ›› 2024, Vol. 47 ›› Issue (2): 74-80.

• 论文 • 上一篇    下一篇

基于改进第一关键集的极化码SCLF译码算法

袁建国1,贺京杰1,张丰果2,黄胜1   

  1. 1. 重庆邮电大学通信与信息工程学院
    2. 重庆邮电大学光电工程学院
  • 收稿日期:2023-03-15 修回日期:2023-04-24 出版日期:2024-04-28 发布日期:2024-01-24
  • 通讯作者: 袁建国 E-mail:yyyyjg@126.com
  • 基金资助:
    国家自然科学基金项目;重庆市研究生科研创新项目

SCLF Decoding Algorithm of Polar Codes Based on the Improved First Critical Set

  • Received:2023-03-15 Revised:2023-04-24 Online:2024-04-28 Published:2024-01-24
  • Contact: Jian-Guo YUAN E-mail:yyyyjg@126.com

摘要: 为了改进极化码串行抵消列表比特翻转(SCLF)译码算法的误码性能, 通过分析已完成译码的比特对未译码比特的影响,提出了一种优化 SCLF 译码算法的算法,即改进关键集精度。以第一关键集(FCS)作为初始关键集,通过计算比特不可靠度的理论值和实际值,筛选出 FCS 中包含串行抵消状态路径的错误比特,并按信道可靠度升序排列形成改进第一关键集(IFCS)。IFCS 能有效提高翻转准确性并减少重译码次数。仿真结果表明,所提算法相较于 RCS-SCLF 译码算法和决策后处理SCLF译码算法具有更好的误码性能和更低的复杂度,同时还可以与小列表循环冗余校验辅助 SCL (CA-SCL)译码算法结合,达到大列表 CA-SCL 译码算法的性能水平。

关键词: 极化码, 第一关键集, 串行抵消列表, 比特翻转

Abstract: In view of the fact that the current successive cancellation list bit-flip (SCLF) does not fully consider the influence of the previous bits decoding on the current bit decoding, this paper proposes a successive cancellation list bit-flip algorithm based on the improved first critical set (IFCS-SCLF). The algorithm takes the first critical set (FCS) as the initial critical set. Then, the theoretical bit unreliability is calculated by the channel error probability and the actual decoding bit unreliability is calculated by the path metric obtained through the cyclic redundancy check aided SCL (CA-SCL). If the bits with actual unreliability is higher than the theoretical value, the error possibility of the bits are higher and will be selected from the SC path status in the first critical set and arranged in ascending order of channel reliability to construct the improved first critical set (IFCS). Finally, the decision results on the SC state path in IFCS are exchanged when the first CA-SCL decoding fails. Simulation results show that the proposed algorithm has better bit error performance and lower complexity than the RCS-SCLF and the D-Post SCLF decoding algorithms, and it can be combined with CA-SCL decoder of small list size to achieve the similar decoding performance of large list size.

Key words: Polar codes, First critical set, Successive cancellation list, Bit-flip

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