Warped Discrete S-Transform

Abstract

This work introduces the warped discrete-time Stransform and the warped discrete S-transform to improve the time frequency representation of the well-known S-transform. The proposed transforms make use of a non-uniform mapping of tones in the frequency domain to increase the time frequency resolution in a specified frequency band. Numerical results show that the warped discrete S-transform can offer better timefrequency representation than discrete S-transform and short time discrete Fourier transform. As a result, it has the potential to increase the performance of techniques based on S-transform that have being designed to analyze non-stationary signals. Finally, it is demonstrated that the discrete S-transform is a particular case of the warped discrete S-transform.