Patent ID: 6785384
Filing Date: 2004-08-31
Classification: H04M

Abstract:
In a circuit comprising (1) a transmit (TX) path configured to convert a digital TX signal into an analog TX signal; (2) a receive (RX) path configured to convert an analog RX signal into a digital RX signal; and (3) an echo cancellation (EC) path configured to generate an analog EC signal, based on the digital TX signal, to be subtracted from the analog RX signal prior to digitization, a method for training an EC estimation filter in the EC path, comprising the steps of:(a) generating a first digital RX signal by applying a first digital TX signal to the circuit with the TX path turned off and with the EC and RX paths turned on; (b) generating a second digital RX signal by applying a second digital TX signal to the circuit with the EC path turned off and with the TX and RX paths turned on; and (c) generating coefficients for the EC estimation filter based on the first and second digital RX signals.