基于小波变换的MSK信号码速率盲估计

针对最小频移键控调制信号的码速率估计问题,提出一种基于Haar小波变换的MSK信号码速率盲估计方法。首先对接收信号作傅里叶变换得到信号频谱,对频谱频点分析粗估计信号的码速率,接着通过粗估计的码速率选取短时傅里叶变换窗函数长度和3个小波尺度,利用短时傅里叶变换得到信号瞬时频率变化,再利用小波的边缘检测特性对信号瞬时频率序列相位跳变点检测,最后对检测结果作频谱分析,估计频率得到MSK信号的码速率。仿真结果表明,高于信噪比门限时本算法可以对MSK信号码速率有效估计。

Blind Symbol Rate Estimation of MSK Signals Based on Wavelet Transform

A new blind estimation algorithm is proposed for the symbol rate estimation of minimum-shift keying (MSK) signals based on wavelet transform.Firstly the Fourier transform of received signals is applied to the spectrum,and then the symbol rate is coarse estimated to choose STFT window length and three wavelet scales.The changes in signal instantaneous frequency are obtained according to STFT,and the jump of phase of the signal instantaneous frequency is detected using Haar wavelet.Finally,the symbol rate of MSK signals is estimated according to the analysis of the spectrum of the test results.The results show the method can estimate the symbol rate effectively when the signal to noise ratio (SNR) is higher than the threshold.