Frequency-warped filter banks and wavelet transforms: a discrete-time approach via Laguerre expansion

In this paper, we introduce a new generation of perfect-reconstruction filter banks that can be obtained from classical critically sampled filter banks by means of frequency transformations. The novel filters are Laguerre type IIR filters that can be directly derived and designed from ordinary orthogonal or biorthogonal filter banks. Generalized downsampling and upsampling operators based on dispersive delay lines are the building blocks of our structures. By iterating the filter banks, we construct new orthogonal and complete sets of wavelets whose passbands are not octave spaced and may be designed by selecting a single parameter.