Extraction of Modulation Features of FSK Signal Based on Time-frequency Joint Analysis

Aimed at the shortcomings that the SNR of wavelet-ridge applied to extracting the modulation features of FSK signals is worse,a novel joint time-frequency analytical method was proposed combining time-frequency reassignment with time-frequency ridge based on the wavelet spectrum.By means of time-frequency reassignment in improving the time-frequency agglomeration of spectrum,the method enhances the SNR performance greatly.The simulation results show that the more accurate estimates can be obtained under the circumstance of low SNR.