Patent ID: 6108412
Filing Date: 2000-08-22
Classification: H04B

Abstract:
An echo canceller for reducing the magnitude of an echo occurring in a return channel of a communication device, said echo canceller comprising:a first processing unit for generating a first echo estimate, said first processing unit including a first input for receiving a signal that is a precursor of the echo in the return channel of the communication device;a second processing unit coupled to said first processing unit for receiving the first echo estimate, said second processing unit including an input for receiving a signal input in the return channel and that is potentially containing echo, said second processing unit being operative to generate an error signal indicative of how closely the first echo estimate models the echo in the return channel of the communication device;a third processing unit including an adaptive filter to generate a second echo estimate, said adaptive filter being characterized by a transfer function, said third processing unit comprising:a) a first input for receiving the signal that is the precursor of the echo;b) a second input for receiving an adaptation signal derived from said error signal, said adaptation signal causing the adaptive filter to alter the transfer function to reduce a difference between the second echo estimate and the echo in the return channel of the communication device;c) a third input for receiving the signal input in the return channel and that potentially contains echo, said third processing unit being operative to condition the signal input at said third input to generate an echo attenuated signal;d) an output for releasing the echo attenuated signal.