AN EFFICIENT APPROACH FOR THE DESIGN OF NEARLY PERFECT-RECONSTRUCTIONQMF BANKS

In this brief, an approach for the design of a class of quadrature mir ror filter (QMF) banks is presented based on a combination of IIR anal ysis filters and FIR synthesis filters. By examining the phase propert y of the all-pass based analysis filter, a condition on the synthesis part for a perfect reconstruction is established, making it possible t o realize a nearly perfect-reconstruction (PR) filter bank by using a nonlinear-phase FIR synthesis filter. The distinct feature of the prop osed mixed IIR/FIR filter bank is that it enjoys both a small reconstr uction error and a low design and implementation complexity.