Design of two channel IIR QMF filters with smooth wavelet functions

This paper presents a rapidly convergent algorithm for the design of pseudo perfect reconstruction two channel IIR filter banks with regular wavelet functions. Regularity is achieved through imposing multiple poles at z=-1 in the analysis and synthesis filter banks. The proposed algorithm yields a stable IIR function with equiripple pass and stop responses and with almost constant group delay. It is shown that the analysis and synthesis banks are of the same complexities and as a result of being realized in a lattice form they are immune from quantization effects. Illustrative examples are also given.