Closed-form approach to design of all-pass digital filters using cepstral coefficients

A simple method for the design of all-pass digital filters is described. In this method, given a desired group delay, the cepstral coefficients corresponding to the denominator of a stable all-pass filter are determined using a least-squares approach. The coefficients of the all-pass filter are then obtained from the cepstral coefficients using a recursive relation.