Minimax design of stable IIR filters with sparse coefficients

Coefficient sparsity of digital filters is of importance as it is directly related to implementation efficiency and cost. To date most work in the field has been focused on finite-impulse response filters. In this paper, the design of sparse digital filters is investigated for a class of IIR filters. We propose a two-phase algorithm that promotes coefficient sparsity, maintains filter´s stability, and optimizes its frequency response to approximate a desired frequency response in minimax sense. A design example is presented to illustrate the proposed algorithm and compare its performance relative to its nonsparse IIR and FIR counterparts.