A class of cosine-modulated causal IIR filter banks

This paper introduces a class of cosine modulated causal IIR filter banks. In the simplest case, the filter banks have near perfect magnitude reconstruction (NPMR). By introducing a phase equalizer one can also obtain near perfect reconstruction (NPR) filter banks. By using filter banks with NPMR instead of NPR, or NPR instead of PR, the arithmetic complexity can be reduced. The paper includes filter design as well as a design example demonstrating the efficiency of the proposed filter banks.