An adaptive time-frequency filtering method for nonstationary signals based on the generalized S-transform

Aiming at the serious interference of the cross term existing in the time-frequency (TF) filtering method, an adaptive TF filtering method for nonstationary signals based on the generalized S-transform is proposed. Firstly the time-frequency distribution spectrum of the signal is got by the generalized S-transform, then the clustered energy of the signal on the time-frequency plane is identified by the TF region extraction algorithm, thirdly the TF filtering factor is constructed based on the distribution characteristic of the effective signal and noise, and finally the random noise is removed from the original signal and the effective signal is remained. Simulation results demonstrate that this method has satisfactory performance in denoising and improving the signal-to-noise ratio. © 2010 Tianjin University of Technology and Springer Berlin Heidelberg.