系统工程与电子技术 ›› 2026, Vol. 48 ›› Issue (5): 1752-1764.doi: 10.12305/j.issn.1001-506X.2026.05.30

• 通信与网络 • 上一篇    下一篇

色噪声下多载波水声通信的高阶调制和软检测

徐锐1,2,3(), 武岩波1,3,4,*(), 朱敏1,3,4()   

  1. 1. 中国科学院声学研究所海洋声学技术实验室,北京 100190
    2. 中国科学院大学电子电气与通信工程学院,北京 100049
    3. 北京市海洋声学装备工程技术研究中心,北京 100190
    4. 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
  • 收稿日期:2024-12-30 出版日期:2026-05-27 发布日期:2026-05-27
  • 通讯作者: 武岩波 E-mail:xurui182@mail.ucas.edu.cn;wuyanbo@ioa.ac.cn;zhumin@mail.ioa.ac.com
  • 作者简介:徐 锐(1996—),男,博士研究生,主要研究方向为正交频分复用水声通信、信号处理
    朱 敏(1971—),男,研究员,博士,主要研究方向为水声通信与组网、声学测速、声学探测、声学系统集成
  • 基金资助:
    国家自然科学基金(61971472);中国科学院战略性先导科技专项项目(A类,XDA22030101)资助课题

High-order modulation and soft detection of multi-carrier underwater acoustic communication with colored noise

Rui XU1,2,3(), Yanbo WU1,3,4,*(), Min ZHU1,3,4()   

  1. 1. Ocean Acoustic Technology Center,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China
    2. School of Electronic,Electrical and Communication Engineering,University of Chinese Academy of Sciences,Beijing 100049,China
    3. Beijing Engineering Technology Research Center of Ocean Acoustic Equipment,Beijing 100190,China
    4. State Key Laboratory of Acoustics,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China
  • Received:2024-12-30 Online:2026-05-27 Published:2026-05-27
  • Contact: Yanbo WU E-mail:xurui182@mail.ucas.edu.cn;wuyanbo@ioa.ac.cn;zhumin@mail.ioa.ac.com

摘要:

在水声通信领域,正交频分复用(orthogonal frequency division multiplexing,OFDM)联合比特交织编码调制技术虽能有效抵抗水声信道频率选择性衰落,但受限于信道状态信息获取不完整和噪声干扰,更高通信速率的高阶调制方案对信道失配更加敏感。旨在提升译码性能与通信可靠性,通过深入探究信道估计误差统计特性,提出极大似然译码度量设计,对译码度量中的似然函数进行修正;同时考虑真实环境噪声特性,基于色噪声假设进一步优化信道估计误差修正译码度量,在色噪声假设下分别对每个子载波估计其噪声信息,结合信道估计误差统计特性对信道估计值进行修正,减少色噪声下信道估计误差对输出软信息的影响。仿真结果显示,色噪声假设(信道估计误差修正)译码度量性能上限更高,且相对传统(信道估计误差忽略)译码度量具有5~6 dB性能提升,相较白噪声假设(信道估计误差修正)译码度量具有1.4 dB性能提升。在最深900 m深海垂直通信试验条件下,经验证在频域上噪声谱密度起伏可达12 dB,所提方法在最高至256阶正交幅度调制(quadrature amplitude modulation,QAM),传输速率为8.84 kbps的OFDM信号实现了译码性能的有效提升,在最远4772 m的通信距离,实现了传输速率为4.42 kbps调制方式为16QAM的可靠OFDM水声通信。

关键词: 水声通信, 正交频分复用, 有色噪声, 信道估计, 对数似然比

Abstract:

In the field of underwater acoustic communication, orthogonal frequency division multiplexing (OFDM) combined with bit-interleaved coded modulation technology can effectively mitigate frequency-selective fading in underwater acoustic channels. However, due to incomplete acquisition of channel state information and noise interference, higher-order modulation schemes aimed at achieving higher communication rates are more sensitive to channel mismatches. To enhance decoding performance and communication reliability, this study delves into the statistical characteristics of channel estimation errors and proposes a maximum likelihood-based decoding metric design, which modifies the likelihood function used in the decoding process. Simultaneously, considering the characteristics of real-world noise, the channel estimation error correction decoding metric is further optimized under the colored noise assumption. The method estimates noise information for each subcarrier with the colored noise hypothesis and corrects the channel estimates based on the statistical characteristics of channel estimation errors, thereby reducing the impact of channel estimation errors on the output soft information in the presence of colored noise. The simulation results show that the color noise assumption (channel estimation error correction) decoding metric achieves a higher performance upper bound and offers a 5-6 dB improvement over the traditional (channel estimation error ignored) decoding metric, while providing a 1.4 dB enhancement compared to the white noise assumption (channel estimation error correction) decoding metric. Under the conditions of the deepest 900 m deep-sea vertical communication test, it was verified that the noise spectral density fluctuation in the frequency domain can reach 12 dB. The proposed method effectively improves decoding performance for OFDM signals with up to 256-order quadrature amplitude modulation (QAM) and a transmission rate of 8.84 kbps. At a communication distance of up to 4772 m, reliable OFDM underwater acoustic communication was achieved with a transmission rate of 4.42 kbps using 16QAM modulation.

Key words: underwater acoustic communication, orthogonal frequency division multiplexing (OFDM), colored noise, channel estimation, log-likelihood ratio

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