Adaptive multimode signal reconstruction from time-frequency representations
Résumé
This paper discusses adaptive reconstruction of the modes of multicomponent AM-FM signals by means of their time-frequency (TF) representation derived from their short time Fourier transform (STFT). The STFT of an AM-FM component or mode spreads the information relative to that mode in the TF plane around curves commonly called ridges. An alternative view, taken in this paper, is to consider a mode as a particular TF domain termed a basin of attraction. Here we discuss two new approaches to mode reconstruction, the first determines the ridge associated with a mode by considering location where the direction of the reassignment vector sharply changes; the technique used to determine the basin of attraction being directly derived from the method used for ridge extraction. A second uses the fact that the STFT of a signal is fully characterized by its zeros (and then the particular distribution of these zeros for Gaussian noise) to deduce an algorithm to compute the mode domains. For both techniques, mode reconstruction is then carried out by simply integrating the information inside these basins of attraction. c The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/ by/4.0/, which permits unrestricted use, provided the original author and source are credited.
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