Designing IIR filter banks composed of allpass sections

In this paper we discuss the design of passband linear phase IIR filter banks composed of allpass sections which are structurally constrained to have low coefficient sensitivity and low roundoff noise level. The design problem is formulated as H_∞ norm minimization which is subsequently converted to a series of linear matrix inequalities (LMI) and solved by semidefinite programming. Simulation results shown that subband filters with passband linear phase property and high stopband attenuation are obtained, and the whole filter bank has small reconstruction error.