| 摘要: |
| 极化码的简化串行抵消列表（Simplified Successive Cancellation List,SSCL）译码提出了R1（Rate1）、R0（Rate0）等多种特殊节点的快速译码算法，一定程度改善了SCL译码复杂度高和时延大的问题，但当节点信息比特数量较大时仍存在大量的冗余计算。针对R1等信息比特较多的节点，提出了一种基于路径度量（Path Metric,PM）的自适应路径选择策略，无需先验信息设置阈值，在不降低SSCL译码性能的条件下能有效降低排序复杂度，减少所需时间步数，提升Polar码译码效率。仿真和实验结果表明，在保证纠错性能的前提下，该算法针对R1节点译码所需的时间步数相对传统SCL译码降低了约83%，相对SSCL降低了约47%，相对快速SSCL降低了约18%。同时，相对基于搜索集和决策函数的SCL译码算法译码效率也有较大提高，其所需时间步数受码字结构及信道环境自适应改变，但不大于快速SSCL译码算法所需时间步数。 |
| 关键词: 极化码 简化串行抵消列表(SSCL)译码 自适应路径选择 路径度量 时间步数 |
| DOI： |
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| 基金项目:2019年重庆市技术创新与应用发展专项重大主题专项(cstc2019jscx-zdztzxX0002) |
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| An adaptive fast successive cancellation list decoding algorithm of Polar codes |
| WANG Ling,ZHANG Zhizhong,DENG Bingguang |
| (School of Communication and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China) |
| Abstract: |
| The simplified successive cancellation list(SSCL) decoding presents fast decoding algorithms for Rate1(R1),Rate0(R0) and other special nodes,which to some extent improves the high complexity and large delay of SCL decoding.However,when the number of information bits of nodes is large,there are still a lot of redundant calculations.For nodes with more information bits,such as R1,an adaptive path selection strategy based on path metric(PM) is proposed,which can improve the sorting complexity and time steps of Polar code decoding process without the prior information setting threshold and reducing the decoding performance.The simulation and experimental results show that,compared with the traditional SCL decoding，SSCL and fast SSCL,the proposed algorithm reduces the time steps required for R1 node decoding about 83%，47% and 18%,respectively，while ensuring errorcorrecting performance.Meanwhile,compared with that of SCL decoding algorithm based on search set and decision function,the decoding efficiency of the proposed algorithm is also greatly improved.The number of time steps is adaptive to the structure of the code words and the channel environment,but it is not greater than the time steps required by the fast SSCL decoding. |
| Key words: Polar code simplified successive cancellation list(SSCL) decoding adaptive path selecting path metric time steps |
