Self-stabilized adaptive allpass filters for phase equalization and approximation

AND APPROXIMATION X. Sun and S.C. Douglas Department of Electrical Engineering Southern Methodist University Dallas, Texas 75275 USA ABSTRACT In this paper, we present a simple adaptive ltering solution to general phase equalization and phase modeling tasks. Our proposed algorithm maintains approximate allpass constraints on the coe cients of an adaptive FIR lter in a self-stabilized manner. An analysis of an idealized IIR version of the technique shows that it converges to a unique stationary point corresponding to the optimal phase relationship between the processed signals. The relationship between the mean-squared error of the estimated phase response and the mean-squared error of the lter coe cients is also derived. Simulations verify that the proposed algorithm performs accurate phase equalization and approximation of unknown systems even in low signal-to-noise ratio conditions.