Instantaneous frequency estimation using robust spectrogram with varying window length

Robust M-periodogram is defined for the analysis of signals with heavy-tail ed distribution noise. In the form of a robust spectrogram it fan be used f or the analysis of nonstationary signals. In this paper a robust spectrogra m based instantaneous frequency (IF) estimator, with a time-varying window length, is presented. The optimal choice of the window length, based on asy mptotic formulae for the variance and bias, can resolve the bias-variance t rade-off in the robust spectrogram based IF estimation. However, it depends on the unknown nonlinearity of the IF. The algorithm used in this paper is able to provide the accuracy close to the one that could be achieved if th e IF, to be estimated, were known in advance. Simulations show good accurac y ability of the adaptive algorithm and good robustness property with respe ct to rare high magnitude noise values.