Approximation of real impulse response using IIR structures

In this paper, we propose a new approach to the approximation and simulation of a real impulse response. Starting from a preliminary analysis of the mixing time, the impulse response is decomposed in the time domain considering the early and late reflections. Therefore, an IIR structure composed of a cascade of second-order sections and four all-pass filters is employed to synthesize the first part of the impulse response, using a parametric optimization process in the frequency domain. Then, a recursive structure composed of comb and all-pass filters is used to synthesize the late reflections, exploiting a minimization criterion in the cepstral domain. Several results are reported taking into consideration a real impulse response, confirming the validity of the proposed approach.