System and method for operating a packet voice far-end echo cancellation system

摘要

A packet voice transceiver adapted to reside at a first end of a communication network and to send an ingress communication signal comprising voice packets to, and receive an egress communication signal comprising voice packets from, a second packet voice transceiver residing at a second end of the communication network. The packet voice transceiver includes a far-end echo canceller that reduces echo that is present in the egress communication signal. The far-end communicates with other functional components of the transceiver system and adapts its behavior based on the activity of the other functional components.

主权项

1. A packet voice transceiver adapted to reside at a first end of a communication network and to send an out-going communication signal containing out-going voice frames to, and receive an in-coming communication signal containing in-coming voice frames from, a second packet voice transceiver residing at a second end of the communication network, the packet voice transceiver comprising:
a jitter buffer adapted to receive the in-coming voice frames, hold each frame of the in-coming voice frames for an adaptable time period, and release each frame at an end of the adaptable time period for further processing; and a far-end echo canceller adapted to reduce echo that is present in the in-coming communication signal based upon the out-going communication signal, the far-end echo canceller including a delay element configured to delay the out-going communication signal receiver by the far-end echo canceller for a variable bulk delay based upon round-trip delay of an echo path from the packet voice transceiver to the second end and back, wherein the jitter buffer notifies the far-end echo canceller of any change in the adaptable time period, and wherein the far-end echo canceller is adapted to adjust the variable bulk delay in response to the notification of the change in the adaptable time period, wherein voice encoding and decoding accounts for at least a portion of non-linearities in the echo path due to network format.