Nonlinear Wigner-Ville Spectrum Estimation using Wavelet Soft-Thresholding
                           Richard G. Baraniuk
                              January 1995


                                ABSTRACT

The large variance of the Wigner-Ville distribution makes smoothing essential 
for producing readable estimates of the time-varying power spectrum of noise 
corrupted signals.  Since linear smoothing trades reduced variance for 
increased bias of the signal components, we explore two nonlinear estimation 
techniques based on soft-thresholding in an orthonormal basis representation.
Soft-thresholding provides considerable variance reduction without greatly 
impairing the time-frequency resolution of the estimated spectrum.

Keywords: Wigner-Ville distribution, wavelet transform, wavelet soft-thresholding.

Presented at the SPIE Technical Conference 2491, "Wavelet Applications for Dual
Use," Orlando, FL, April 1995.

Email: richb@rice.edu