S-transform based on analytic discrete cosine transform for time-frequency analysis

This paper presents a new S-transform based on Analytic Discrete Cosine Transform (ADCT). This has been achieved by the use of a Discrete Fourier Transform (DFT) derived from DCT, the analytic DCT which preserves the desirable properties of DCT, viz., the improved frequency resolution and significant reduction in leakage compared to those of conventional DFT. The new S-transform will provide improved performance in terms of frequency resolution and energy concentration (along the frequency axis) as compared to those of S-transform based on OFF. The application of the proposed method to different types of test signals reveals its improved performance in terms of time resolution at high frequencies, frequency resolution in the low frequency region and improved energy concentration. (c) 2014 Elsevier B.V. All rights reserved.