基于LFM信号的MPSK水声信号盲解调

Blind Demodulation of MPSK Underwater Acoustic Signal Based on LFM Signal

在浅海条件下,复杂多变的信道导致非合作水声信号在解调时遇到很多困难。线性调频信号常作为水声通信的导频信号,通过对导频信号进行参数估计和数据处理,可提取信道参数信息并用于信号解调。浅海中接收的非合作水声信号受到多径效应、脉冲噪声的严重影响,论文给出了一种基于线性调频信号分析与处理的盲解调方法,通过对线性调频信号进行强度分析,设置非线性函数抑制噪声,获取信道信息,并初始化均衡器的系数,提高了信号的盲解调性能。仿真结果证明了该方法的有效性。

In shallow water,the complex and changeable channel leads to many difficulties in the demodulation of non cooper⁃ative underwater acoustic signals.LFM signal is often used as the pilot signal of underwater acoustic communication.Through param⁃eter estimation and data processing of the pilot signal,the channel parameter information can be extracted and used for signal de⁃modulation.The non cooperative underwater acoustic signal received in shallow water is seriously affected by multipath effect and impulse noise.This paper presents a blind demodulation method based on linear frequency modulation signal analysis and process⁃ing.Through the strength analysis of linear frequency modulation signal,nonlinear function is set to suppress noise,channel infor⁃mation is obtained,and the coefficients of equalizer is initialized,the blind demodulation performance of the signal is improved.Simulation results show the effectiveness of this method.