Nonlinear Wigner-Ville spectrum estimation using wavelet soft-thresholding
Richard G. Baraniuk · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1995
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.