Multitaper Wigner and Choi-Williams distributions with pre-determined doppler-lag bandwidth and sidelobe suppression

In this paper, a penalty function is designed and used in the computation of multitapers which correspond to the Wigner and Choi-Williams distributions. The resulting multitaper spectrogram will approximately fulfill the concentration of the distribution but will additionally suppress the cross-terms outside a predetermined Doppler-lag bandwidth. The specific region as well as the amount of cross-term suppression is determined by parameters of the penalty function. The proposed method uses a limited number of multitapers which results in computationally efficient calculations. The time-frequency concentration and resolution of the proposed method and the original distribution are compared and the performance for signals disturbed by white noise is also evaluated. Estimation of event related potentials disturbed by EEG exemplify the use of the method. (C) 2010 Elsevier B.V. All rights reserved.