Improved digital all-pass filter design
Zhiyuan Xie · Journal of North China Electric Power University · 2004
The improved method is based on the relation between the complex Cepstrum and the stable minimum- phase sequence. Given the desired group delay, the complex Cepstrum coefficients are computed in such a way thatthedenominatorgroup delay is approximated in the WeightedLeast Square sense. Usingthecomplex Cepstrum coefficients, theall-pass denominator coefficientsare obtained based on the relation betweenthecomplex Cepstrum and the stable minimum-phase sequence. The all-pass transfer function is completely determined from its denominator coefficients. The group delay of designed filter can approximate the desired group delay in all band.