New polyphase filter bank-based analysis/synthesis systems

Analysis/synthesis systems based on polyphase filter banks are presented for the 1-D and 2-D cases. Bandpass filters required in subband channels are constructed from nonsymmetric frequency translations of a prototype low-pass filter G(ω). Constraints on the frequency response G(ω) for perfect aliasing cancellation and signal reconstruction are then derived. An efficient structure consisting of a polyphase network and the fast Fourier transform (FFT) is proposed for realizing an analysis/synthesis system with an arbitrary number of subband channels and is shown to be more computationally efficient than other systems based on polyphase filter banks. The 1-D theory can be extended in two dimensions. The constraints on the frequency response G(ω₁, ω₂) of a 2-D prototype low-pass filter are similar to those of the 1-D case if G(ω₁, ω₂ ) is nonseparable. Computer simulations confirming the theoretical work are shown