On the theory and design of a class of PR causal-stable IIR Non-uniform Recombination Cosine Modulated Filter Banks

摘要

This paper studies the theory and design of a class of perfect reconstruction (PR) causal-stable nonuniform recombination cosine modulated filter banks (RN CMFBs) with DR filters. It is based on the RN CMFB previously proposed by one of the author. A PR FIR RN CMFB of similar specification is first designed. The prototype filters of the CMFBs are then model reduced to obtain a nearly PR (NPR) IIR RN CMFB by modifying a model reduction technique proposed by Brandenstein and Unbehauen. With these NPR HR RN CMFBs as initial guess, PR ITR RN CMFB with very good frequency characteristics can be obtained readily by solving a constrained nonlinear optimisation problem using for example the function firuncom from MATLAB. Design results show that the proposed method is very effective in designing PR RN HR CMFBs with good frequency characteristics and different system delays.