QUADRATURE FILTER AUGMENTATION OF ECHO CANCELER BASIS FUNCTIONS

摘要

An echo canceler has its otherwise conventional tapped delay tine basis functions augmented with at least one pair of basis functions realizing two quadrature responses of a complex pole. The frequency of this complex pole is selected as substantially equal to the frequency of the dominant pole of a highpass filter inserted into the echo path of the echo cancels, where the dominant pole is the pole closest to the unit circle. This echo canceler arrangement resul ts in a substantial improvement in attainable echo-return-loss enhancement (ERLE).