基于垂直阵模态分解的低频水声信号盲解卷处理研究

Blind deconvolution of low frequency acoustic signals based on mode decomposition using vertical liner array in shallow water

研究了基于人工时反处理的水声信号盲解卷方法,并在此基础上提出了一种基于简正波模态分解的低频水声信号的盲解卷处理方法。该方法适用于浅海波导中垂直阵接收的远程低频水声信号的盲解卷处理。该方法首先从浅海中垂直阵接收的信号中提取(估计)出波导中传播的简正波模态函数信息,然后,根据估计的模态函数信息通过模态滤波来实现水声信道盲解卷处理。针对典型的浅海波导环境,进行了计算机仿真试验,结果表明:(1)远程低频条件下,模态分解方法可以从垂直阵接收的信号中提取出波导中有效传播的模态函数信息,因此这种方法解决了目前人工时反处理方法需要准确的模态函数先验信息的问题;(2)在一定带宽条件下,接收信号信噪比较低时,本文给出的这种基于模态滤波的盲解卷方法比人工时反处理具有更好的解卷性能。

On the base of the idea of blind deconvolution using artificial time reversal,a blind deconvolution method based on normal mode decomposition is proposed in this paper.This method is suitable for the blind deconvolution of the low frequency underwater acoustic signals received by a vertical liner array（VLA） in shallow water.Firstly,the normal modes of acoustic propagation in the shallow water are extracted（estimated） by mode decomposition from the signals received by a vertical liner receiver array（VLA）.Then,the blind deconvolution processing to recover or reconstruct the source signal is achieved by mode filtering according to the estimated normal modes.Numerical simulations in typical shallow water environment demonstrate the effectiveness of the proposed method.The simulation results indicate that the normal modes of the low frequency acoustic field in the shallow water can be extracted successfully from the signals received on VLA by mode decomposition,thus the method presented in this paper remedies the shortages of conventional blind deconvolution method using artificial time reversal processing which requires exact normal mode information.And under the condition of certain signal bandwidth,the performance of the blind deconvolution using mode filters presented in this paper is better than that using artificial time reversal.