On the design of L/sub p/ IIR filters with arbitrary frequency response

This paper introduces an iterative algorithm for designing IIR digital filters that minimize a complex approximation error in an L/sub p/ sense. The algorithm combines ideas that have proven successful in the similar problem of L/sub p/ FIR filter design. We use iterative prefiltering techniques common in applications such as parameter estimation together with an iterative reweighted least squares (IRLS) method. The result is a double iterative approach that generates IIR filters of arbitrary magnitude and phase response and arbitrary numerator and denominator orders. Such filters can be used in a variety of applications in which the typical L/sub 2/ or L/sub /spl infin// error criteria might not be suitable.