The problems of difficulty and low efficiency in decomposing multicomponent nonstationary nonlinear sig-nal with complex time-frequency characteristics such as contiguity,overlap and intermittency in time-frequency domain are solved.Based on the time-frequency distribution of signal,a multicomponent nonstationary signal decomposition method called time-frequency filtering decomposition(TFFD)is proposed.TFFD gets the fitting IF curve which is consistent with the instantaneous frequency(IF)of the components by fitting the time-frequency datum points which can reflect the instan-taneous characteristics and laws of the components in the signal.Based on the time-frequency coordinates of fitting IF curve,the distribution area of component is determined by setting the distance threshold condition.Thus,a time-frequency filter bank is constructed,which is based on fitting IF curve time-frequency coordinates as the central frequency and the bandwidth of distribution area as the passband width,to achieve time-frequency filtering decomposition for multicomponent signal.Through the analysis of the simulation and the actual signal with the representative time-frequency characteristics,and the comparison with the classical signal decomposition methods,it is proved that the TFFD method has good decompo-sition ability and efficiency.
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