Fast short-time orthogonal wavelet packet transform algorithms

Abstract

Orthogonal wavelet packet transforms, presented recently as powerful tools for nonstationary signal processing, suffered from the lack of efficient and time-domain transparent algorithms for their implementation. We present an overlapped block lattice structure that allows fast short-time wavelet packet transform algorithms to be built in an equivalent manner to other short-time transforms, such as the short-time Fourier transform (STFT) based on the fast Fourier transform (FFT) algorithms. The outputs obtained with the overlapped block lattice are equivalent to those achieved by the well known tree-structured filter bank approach, though the implementation algorithms are different.