An adaptive STFT using energy concentration optimization

This work is inspired by a kind of S-transforms which employ a window width optimization strategy. Since the main objective of their methods is to adjust the window width passively by controlling the standard deviation function of the Gaussian window, we realize it in a way more straightly. Namely, we propose a new window which can optimize the shape and width directly according to a modified concentration measure. Notice that this window is not the function of frequency, so the corresponding time-frequency representation is not under the framework of S-transform. It is a kind of adaptive short-time Fourier transforms. The performance of the method is tested by a set of synthetic FM signals. The appropriate window of the proposed method can be given definitely and the method can achieve high energy concentration in low SNR.