absYSTEM AND METHOD FOR ECHO CANCELLATION

摘要

A line card (22) for coupling a subscriber line (18) to a switching network (17) the line card (22) comprising an echo canceling circuit (42) for reducing an echo signal received from the network and perceived at a user instrument coupled to the subscriber line. The network cancellation circuit utilizes a network model (44) to predict an echo replica signal which is then subtracted either from the transmit (47) or receive (49) signals to the network. The line card (22) may include a far end echo cancellation circuit, a near end echo cancellation circuit or a combination of both.