Theory and lattice structures for multichannel FIR filter banks with customized filter lengths

This paper systematically investigates the existence conditions, lattice structures and designs for several classes of M-channel FIR filter banks (FBs) with flexible filter lengths. The motivation for such FBs is to overcome the limitations of traditional methods and to achieve a better trade-off between complexity and length. First, the existence conditions are derived for such FBs. Then, various lattice structures are developed for several classes of FBs. Finally, design examples are presented to validate these structures and to compare different classes of FBs.