Page 64 - 《应用声学》2022年第1期

第 41 卷 第 1 期 Vol. 41, No. 1
2022 年 1 月 Journal of Applied Acoustics January, 2022

⋄ 研究报告 ⋄

基于Polar码的水声通信信源信道联合译码方法

胡承昊 1,2 台玉朋 1 汪 俊 1 胡治国 1 王海斌 1†

(1 中国科学院声学研究所 声场声信息国家重点实验室 北京 100190)
(2 中国科学院大学 北京 100049)

摘要：水声信道时延扩展较长，频域选择性衰落严重，导致水声通信提升可靠性困难。同时，水声通信实际发
送的信源中通常存在残留冗余，传统方法难以利用这部分冗余，从而导致一定的带宽浪费。针对该问题，提出
了一种基于 Polar 码的水声通信信源信道联合译码方法。该方法根据 Polar 码的译码结构，以信源状态转移关
系为基础构建信源信道联合译码网格图，综合信源转移概率和信道转移概率计算统一的序列后验概率，实现
了信源译码和信道译码的一体化联合优化。该方法能够利用信源符号间相关性导致的残留冗余抵抗信道差
错，在不降低通信速率的情况下进一步提高水声通信系统可靠性。湖上实验结果表明，在相同条件下，所提方
法可将系统误码率由传统分离译码的 1.9×10 −2 降低为 4.0×10 −4 ；当传输图像序列时，传统分离译码方法的
误码率为 3.7×10 −3 ，而所提方法则在实验中实现了无误码通信。
关键词：水声通信；Polar 码；信源信道联合译码；湖上实验
中图法分类号: TN929.3 文献标识码: A 文章编号: 1000-310X(2022)01-0060-10
DOI: 10.11684/j.issn.1000-310X.2022.01.007

A joint source-channel decoding algorithm based on polar codes for

underwater acoustic communication

HU Chenghao 1,2 TAI Yupeng 1 WANG Jun 1 HU Zhiguo 1 WANG Haibin 1

(1 State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China)
(2 University of Chinese Academy of Sciences, Beijing 100049, China)

Abstract: It is difficult to improve the reliability of underwater acoustic communication (UAC) due to the
long-time delay and severe frequency fading of underwater acoustic channels. On the other hand, there are
always some source residual redundancies in practical UAC. Traditional methods cannot use these redundancies.
That leads to some waste of bandwidth. To overcome these problems, a joint source-channel decoding algorithm
based on polar codes for UAC is proposed. According to the decoding structure of polar codes, the joint source-
channel decoding trellis is constructed based on the source transfer relationship. The posterior probabilities are
computed by combining the source transfer probability and the channel transfer probability. In this way, the
source decoding and channel decoding are optimized jointly. This algorithm can take advantage of the source
residual redundancies for error control decoding and can improve the reliability of UAC without reducing the
communication rate. The lake experimental results show that the proposed algorithm can reduce the bit error
rate (BER) from 1.9×10 −2 of the traditional separate decoding algorithm to 4.0×10 −4 . When transmitting
photographs, the proposed algorithm can reduce the BER from 3.7×10 −3 of the traditional separate decoding
algorithm to 0.
Keywords: Underwater acoustic communication; Polar codes; Joint source-channel decoding; Lake experiment

2021-03-05 收稿; 2021-04-19 定稿
作者简介: 胡承昊 (1994– ), 男, 山东济南人, 博士研究生, 研究方向: 信号与信息处理。
通信作者 E-mail: whb@mail.ioa.ac.cn
†