Echo canceller for voip networks

摘要

An echo canceller in an IP network includes an adaptive filter that models the echo path between a receiving output port of the echo canceller and a sending input port. The adaptive filter filters a receiving input signal to generate an estimate of an echo signal. The estimate of the echo signal is subtracted from a sending input signal to cancel the echo in the sending input signal and to generate a sending output signal. A packet loss detection circuit detects when packet loss occurs in the echo path. Responsive to detection of packet loss in the echo path, the echo canceller applies packet loss concealment to either the sending output signal or the receiving input signal.