1. US5912966 - Enhanced echo canceller for digital cellular application

An echo cancelling system for communication systems. The system includes an adaptive filter that processes the speech signal re-constructed by a voice decoder to generate an echo estimate. The echo estimate is subtracted from the echo containing signal propagating in the communication link to remove or at least reduce the echo corruption. The tap coefficients of the adaptive filter are established on the basis of an error signal that is representative of difference between the echo estimate and the actual echo and on the basis of a signal element that is a component of the re-constructed speech signal. The signal element is highly decorrelated to enable the adaptive filter to converge faster and manifest an improved echo return loss enhancement.