DAFx-2011 - Paris

This paper describes an improvement of the generalized reassignment method for estimating the parameters of a modulated real sinusoid. The main disadvantage of this method is decreased accuracy for high log-amplitude and/or frequency changes. One of the reasons for such accuracy deterioration stems from the use of the Fourier transform. Fourier transform belongs to a more general family of integral transforms and can be defined as an integral transform using a Fourier kernel function - a stationary complex sinusoid. A correlation between the Fourier kernel function and a non-stationary sinusoid decreases as the modulation of the sinusoid increases, ultimately causing the parameter estimation deterioration. In this paper, the generalized reassignment is reformulated for use with an arbitrary kernel. Specifically, an adaptive polynomial-phase Fourier kernel is proposed. It is shown that such an algorithm needs the parameter estimates from the original generalized reassignment method and that it improves the Signalto-Residual ratio (SRR) in the non-noisy cases. The drawbacks concerning the initial conditions and ways of avoiding a close-tosingular system of linear equations are discussed.

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