Patent ID: 6263078
Filing Date: 2001-07-17
Classification: H04M

Abstract:
An echo canceller system comprising:a receive path to receive an incoming signal;send means for enabling transmissions that are responsive to an outgoing signal from a source, said send means having a first output line and a second output line for enabling alternative connections between said source and an output terminal of said send means;first echo-cancelling means coupled to said first output line for generating a first predicted-echo signal that is removed from said outgoing signal for filtering echo in said outgoing signal to produce a first echo-cancelled signal on said first output line, said first echo-cancelling means being responsive to said first echo-cancelled signal as a first error signal and being responsive to said incoming signal as a reference signal for computing said echo in said outgoing signal;second echo-cancelling means coupled to said second output line for generating a second predicted-echo signal that is removed from said outgoing signal for filtering said echo in said outgoing signal to produce a second echo-cancelled signal on said second output line, said first and second echo-cancelling means being configured such that said filtering of said outgoing signal along said second output line by said second echo-cancelling means bypasses said filtering of said outgoing signal along said first output line by said first echo-cancelling means, said second echo-cancelling means being responsive to said second echo-cancelled signal as a second error signal and being directly responsive to said first predicted-echo signal as a second reference signal for computing said echo in said outgoing signal; andselecting means configured to receive said first echo-cancelled signal and said second echo-cancelled signal for selectively transmitting one of said first echo-cancelled signal and said second echo-cancelled signal via said output terminal.