Design of causal stable IIR filter banks with powers-of-two coefficients

We introduce an efficient method for the design of causal stable IIR filter bank (FB) with Powers-of-two coefficients. Ladder structure is used to construct the IIR FBs with perfect reconstruction (PR). In the proposed method, FBs with real coefficients are first designed and an iterative procedure is then employed to discretize the coefficients. A sensitivity measure is introduced to determine the order of coefficients to be discretized. To ensure the stability of the IIR filters, the stability triangle is used. Even though the method is suboptimal, it avoids integer programing and yields satisfactory results.