Estimation of stable all-pass transfer functions for delay equalization based on least-squares minimization and wavelet transform

In this paper, we present a generalized optimal stable all-pass digital filter design algorithm that supports (1) arbitrary phase response specifications, (2) a corrective system designed to make the phase delay of a magnitude-filter substantially constant over a desired frequency range, (3) estimation of the delay 3 of the best performed equalizer, (4) stability, and (5) wavelet-based non-uniform sampling of the phase response of the magnitude-filter whose delay is to be equalized.