Least Squares Multi-Window Evolutionary Spectral Estimation

We present a multi–window method for obtaining the time-frequency spectrum of of nonstationary signals such as speech and music. This method is based on optimal combination of evolutionary spectra that are calculated by using multi–window Gabor expansion. The optimal weights are obtained by using a least square estimation method. An error criterion that is the squared distance between a reference time–frequency distribution and the combination of evolutionary spectra is minimized to determine the weights. Examples are given to illustrate the effectiveness of the proposed method. Key-Words: Time-frequency analysis, Evolutionary spectrum, Multi-window time-frequency analysis.