用小波变换的模极大值提取调制信号频率

Extraction of Frequency from Modulated Signals by Modulus Maxima of Wavelet Transform

利用小波变换系数的模值与信号奇异性指数之间的关系,从调频信号中提取出调制信号的频率。其方法是:对调频信号进行小波变换,取适当尺度上的小波系数进行平方,得到小波变换模极大值的分布曲线,对该曲线进行小波强制滤波,得到反映调制信号频率的光滑曲线,计算该曲线的频率,即可得调制信号的频率。经过计算机仿真,证明该方法是可行的。

Frequency of modulated signals is extracted from frequency-modulated signals by using the relationship between the modulus of wavelet transform coefficient and the singular exponent. In this method, wavelet transform of frequency-modulated signals is performed, and then, the wavelet transform coefficient on moderate scale is squared to obtain the distribution curve of modulus maxima of the wavelet transform, which is coercively filtrated, thus generating a smooth frequency curve of modulated signals. This method is validated by computer simulation.