Nonstationary signal enhancement using the wavelet transform

Conventional signal processing typically involves frequency selective techniques which are highly inadequate for nonstationary signals. In this paper, the authors present an approach to perform time-frequency selective processing using the wavelet transform. The approach is motivated by the excellent localization, in both time and frequency, afforded by the wavelet basis functions. Suitably chosen wavelet basis functions are used to characterize the subspace of signals that have a given localized time-frequency support, thus enabling a time-frequency partitioning of signals. A practical implementation scheme using filter banks is also presented, and the effectiveness of the approach over conventional techniques is demonstrated.