摘要
高阶调制超奈奎斯特信号可以提高水声通信系统的频谱效率。为消除干扰需要进行多普勒时频偏移补偿和符号均衡。为此提出基于相关峰sinc插值的连续定时估计方法,估计每个接收符号时变多普勒定时偏移量,通过多普勒补偿后使每帧数据的信道近似时不变。并提出基于噪声重构的向量近似消息传递信道估计Turbo均衡,利用信道估计值来重构噪声并计算噪声方差,通过内外两层迭代来挖掘符号间的约束增益,抑制符号间干扰。距离为900m的垂直水声通信海试结果表明,采用所提方法可以实现频谱效率为1.85bits/(sHz)的超奈奎斯特信号无差错传输。
High order modulation faster-than-Nyquist technology can improve the spectral efficiency of under water acoustic communication systems.To eliminate interference,Doppler time-frequency offset compensation and symbol equalization are required.Therefore,a continuous timing estimation method based on correlation peak sinc interpolation is proposed,which compensate for the time-varying Doppler effect of each received symbol,making the channel experienced by each data frame after compensation approximately unchanged in time.And a Turbo equalization based on noise reconstruction vector approximate message passing is proposed,which uses estimated channel to reconstruct noise and calculate noise variance.The constraint gain between symbols is mined through inner and outer layers of iteration to suppress inter symbol interference.The sea experiment results of vertical underwater acoustic communication at a distance of 900 meters show that the proposed method can achieve error free transmission of faster-than-Nyquist signals with a spectral efficiency of 1.85 bits/(s·Hz).
作者
褚润聪
武岩波
朱敏
CHU Runcong;WU Yanbo;ZHU Min(Laboratory of Ocean Acoustic Technology,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of Acoustics,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China;Beijing Engineering Technology Research Center of Ocean Acoustic Equipment,Beijing 100190,China)
出处
《应用声学》
北大核心
2025年第2期441-453,共13页
Journal of Applied Acoustics
基金
国家自然科学基金项目(61971472)
中国科学院战略性先导科技专项A类(XDA22030101)
国家重点研发计划项目(2021YFC2800200,2021YFC2801303)。
关键词
水声通信
高阶调制
超奈奎斯特
TURBO均衡
消息传递
Underwater acoustic communication
Higher-order modulation
Faster-than-Nyquist
Turbo equal ization
Message passing
