Patent ID: 7907977

Claim:
A communications system comprising: a transceiver configured for sending a signal and receiving a signal in communications with remote transceivers, wherein the transceiver is subject to coupling between a downlink received signal and an uplink send signal, forming an echo path; wherein said communications are received at least partly through at least one downlink Codec in a compressed format employing a relatively more redundant component and a relatively less redundant component; an echo canceller associated with the transceiver, the echo canceller comprising an adaptive finite impulse response filter configured to correlate at least a component of the received signal with at least a component of the send signal, and to converge on a set of coefficients that characterize the echo path; wherein the echo canceller further comprises a filter for applying the received signal to the set of coefficients to generate a predicted echo signal and a summing node at which the predicted echo signal is subtracted from the send signal, thereby removing echo from the send signal; wherein correlation of the received signal and the send signal is based upon a pre-whitened component of the received signal, and wherein the pre-whitened component is derived from the relatively less redundant component of the received signal of the compressed format.