Local instantaneous frequency estimation of multi-component signals

Abstract

We present a method for estimating the instantaneous frequency (IF) of multi-component signals. This method involves the calculation of a time-frequency energy density of the signal, then obtaining a local IF estimate from this joint density. Time-frequency energy density is calculated as a least squares optimal combination of multi-window Gabor based evolutionary spectra. The optimal weights are obtained by minimizing an error criterion that is the difference between a reference time-frequency distribution and the combination of evolutionary spectra. IF of the signal components is estimated from the final evolutionary spectrum at small time-frequency regions as the average of frequencies at each time. As such, local IF information of a multi-component signal can be estimated in the time-frequency plane. (C) 2007 Elsevier Ltd. All rights reserved.