Theory and design of a class of M-channel IIR cosine-modulated filter banks

Abstract—This letter proposes a method for designing a class of-channel, causal, stable, perfect reconstruction (PR) IIR co-sine-modulated filter banks (CMFB). The proposed CMFB has the same denominator for all its polyphase components in the proto-type filter. Therefore, the PR condition is considerably simplified, and it is relatively simple to satisfy the PR and the casual-stable re-quirements of the IIR CMFB. Design examples show that the pro-posed IIR CMFB has sharper cutoff, higher stopband attenuation, and passband flatness than its FIR counterparts, especially when the system delay is small. Index Terms—Causal stable, cosine-modulated, filter banks, IIR, perfect reconstruction