Patent ID: 6480532
Filing Date: 2002-11-12
Classification: H04B

Abstract:
A bi-directional communications device including both an analog processing domain and a digital processing domain, comprising:a transmit channel spanning the digital and analog processing domains for processing a transmit signal; a receive channel spanning the analog and digital processing domains for processing a receive signal; a line interface in the analog processing domain for transmitting the transmit signal over a communications line, and for receiving the receive signal as corrupted by an unwanted echo component of the transmit signal from the communications line; and an echo channel spanning the digital and analog processing domains and including: a tap in the digital processing domain for tapping the transmit signal from the transmit channel; an adaptive filter in the digital processing domain for processing the tapped transmit signal to generate an echo cancellation signal, the adaptive filter having a transfer function substantially matching an echo transfer function which defines a relationship at the interface between the transmit signal and the unwanted echo component; and a converter for converting the echo cancellation signal to an analog echo cancellation signal; and wherein the receive channel further includes a summer in the analog processing domain for subtracting the analog echo cancellation signal from the echo component corrupted receive signal and outputting a corrected receive signal for further processing in the receive channel.