Patent ID: 6061444
Filing Date: 2000-05-09
Classification: H04B

Abstract:
An echo canceler learning method applicable to an echo canceler employed in a communication line network including a hybrid circuit for converting signals between a four-wire trunk and a two-wire loop, said four-wire trunk comprising a first transmission line for transmitting a signal through the hybrid circuit to said two-wire loop and a second transmission line for transmitting a signal coming from said two-wire loop through the hybrid circuit, said echo canceler learning method comprising the steps of:generating a pilot signal and supplying the pilot signal on said first transmission line;calculating a coefficient necessary for generating an echo replica based on a correlation established between the pilot signal supplied on said first transmission line and the signal on said second transmission line;judging whether a calling is issued from said four-wire trunk or said two-wire loop;effecting the learning of said echo canceler using a first learning method when it is judged that the calling is issued from said four-wire trunk; andeffecting the learning of said echo canceler using a second learning method when it is judged that the calling is issued from said two-wire loop.