Design of biorthogonal filter banks composed of linear phase IIR filters

Since IIR filters have lower computational complexity than FIR filters, some design methods for IIR filter banks have been presented in the recent literature. Smith et al. (1990) have proposed a class of linear phase IIR filter banks. However this method restricts the order of the numerator to be odd and, moreover, has some drawbacks. In this paper we present two design methods for linear phase IIR filter banks. One is based on Lagrange-Multiplier method, in which optimal IIR filter banks in least squares sense are obtained. In the other approach, IIR filter banks with the maximum number of zeros are derived analytically.