On arbitrary-length, M-channel linear-phase FIR filter banks
This paper investigates the existence of a large subclass of M-channel linear-phase perfect-reconstruction FIR filter banks-systems with analysis and synthesis filters of length L/sub i/=K/sub i/M+/spl beta/, where /spl beta/ is an arbitrary integer, 0/spl les//spl beta/<M, and K/sub i/ is any positive integer. For this subclass of systems, and for any arbitrary channel M, we first derive the necessary conditions for the existence of linear-phase perfect-reconstruction filter banks. Next, we turn our attention to a large class of linear-phase paraunitary filter banks, those with even M and even /spl beta/, and develop a simple lattice structure for this case. Finally, several design examples are presented to confirm the validity of the theory.