A novel method for the design of maximally decimated pairwise FIR filter banks

This paper presents a new method for the design of maximally decimated perfect reconstruction M-bank FIR filters with symmetrical response around /spl pi//2, where m is even. The method is based on the construction of a new unitary transformation matrix from which the different filter banks are derived. Unlike the commonly used unitary matrices where every matrix section is constructed using only two parameters, the proposed new transformation has the flexibility of assigning three parameters to every section. These parameters are optimally determined to minimize the magnitude deviation of each filter bank from its ideal response. As a result, better stopband attenuation is achieved for the same filter complexity. Illustrative examples are given to show that for the same filter complexity, the proposed method offers significant improvement over already published results, as well as over realizations that relax the pairwise properly.