Time-Frequency Filtering Based on Model Fitting in the Time-Frequency Plane

The modulus of time-frequency representations, like the short-time Fourier or wavelet transforms, of a multicomponent signal exhibit ridges from which one usually computes estimations of the instantaneous frequencies of the modes making up the signal. But, due to the finite frequency resolution, the estimations thus obtained are piecewise constant. Our aim in this letter is to introduce a novel method for the estimation of the instantaneous frequencies of the modes based on the modeling of the modulus of the short-time Fourier transform, and then to propose a novel technique for mode retrieval. Numerical experiments carried out on both simulated and real signals demonstrate the benefits of the proposed approach over others based on the short-time Fourier transform.