基于小波变换的BDPSK信号盲解调算法

A Blind Demodulation Algorithm for BDPSK Signal Based on Wavelet Transform

在BDPSK信号解调中,非合作信号的载频估计误差或高动态环境引起的多普勒频移都会使得解调性能恶化,甚至无法解调。针对这个问题,提出了一种基于morlet小波变换的BDPSK信号盲解调算法。算法利用BDPSK信号小波系数模的幅度突变信息,完成符号率估计、符号同步和符号识别。算法无需载波恢复,对载频估计误差也不敏感,并且能够适应载频时变的BDPSK信号。仿真结果表明,算法具有较高的符号率估计性能和同步性能,盲解调性能比理论值恶化量约为1.6dB。

Demodulation of BDPSK signal is greatly degraded, and sometimes even can＇t be achieved resulted from carrier frequency estimation error of non - cooperation signal or Doppler shift under dynamic environment. A blind demodulation algorithm is proposed for BDPSK signal, which accomplishes the demodulation processing after symbol rate estimating, symbol synchronizing and symbol recognizing by mutations of wavelet module coefficients of signals. The algorithm, which does not require carrier recovery and has low sensitivity＇ to carrier frequency estimation error, is suitable for time - varying frequency signal. The simulation result demonstrates that the algorithm has a good performance for symbol rate estimation and symbol synchronization, and the performance of blind demodulation is lower than the theory lower bound by 1.6dB.