Cepstral synthesis of minimum-phase FIR and IIR digital filters

A new technique for designing causal and minimum-phase FIR and IIR digital filters is presented. Here, the deviation from a desired quefrency response is minimised using the Fletcher-Powell algorithm. As a consequence, this leads to an optimisation of both log-magnitude response and phase response. Therefore, the method is of special interest for both equalisers and allpasses. It works with real parameters which represent the poles and zeros of the system.