一种低信噪比二相编码信号时频分析方法

A Time-Frequency Analysis Method for Low SNR BPSK Signal

针对时频分析方法在低信噪比条件下识别二相编码信号相位突变点效果较差的问题,提出了一种在低信噪比条件下的相位编码信号相位突变点检测的新方法。新方法首先估计信号的载频,然后得到信号载频处STFT变换的幅值矩阵,设定合适的阈值后进行积累运算,最后再设置一定的阈值检测出相位突变点的位置。仿真结果表明新方法有效可行,能够在更低的信噪比条件下准确检测出信号的相位突变点位置。

Because time-frequency analysis methods can not have a higher detection rate for BPSK signal phase catastrophe-points under low SNR environments,a new BPSK signal phase catastrophe-points detection method was developed for low SNR condition.First,it estimates the signal carrier frequency and calculates the amplitude matrix of STFT transform at the signal carrier frequency.Second,it sets a threshold and then accumulates the useful value.At last it sets a proper threshold to detect phase catastrophe-points.The simulation proved the validity of the method and showed that the method can effectively improve the BPSK signal catastrophe-points detection under low SNR.