Telephonic communications – Subscriber line or transmission line interface – Network interface device
Patent
1991-01-24
1993-03-09
Dwyer, James L.
Telephonic communications
Subscriber line or transmission line interface
Network interface device
370 321, 379406, H04B 320
Patent
active
051931125
ABSTRACT:
Double talk is rapidly detected for effectively preventing degradation of echo cancellation in a long distance telephone communications system. An echo estimator includes a transversal filter and receives an incoming signal and tap coefficients, and then adaptively produces an estimated echo signal. A subtractor is adapted to subtract the estimated echo signal from an echo signal applied thereto, and outputting an error signal indicating residual echo. A tap coefficient updating circuit is coupled to receive the error signal and the incoming signal and the tap coefficients, and renews the tap coefficients. A double talk detector is coupled to receive the error signal and the incoming signal and the echo signal. The double talk detector issues a double talk detection signal in the event that a cross-correlation value between the incoming and echo signals is less than a first predetermined level while an estimated echo cancellation is larger than a second predetermined level.
REFERENCES:
patent: 4587382 (1986-05-01), Yang
patent: 4621172 (1986-11-01), Kanemasa et al.
patent: 4918727 (1990-04-01), Rohrs et al.
Dwyer James L.
NEC Corporation
Shehata M.
LandOfFree
Arrangement and method for rapidly detecting double talk in long does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Arrangement and method for rapidly detecting double talk in long, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Arrangement and method for rapidly detecting double talk in long will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-214860