Multiplex communications – Duplex – Transmit/receive interaction control
Patent
1996-10-01
2000-03-28
Pham, Chi H.
Multiplex communications
Duplex
Transmit/receive interaction control
379406, H04B 320, H04M 100
Patent
active
060440686
ABSTRACT:
An echo cancellation method and apparatus (20) determines whether a window W(m) of samples on an incoming communications path (30) contains silence, the window W(m) including the sample obtained at time t(m) and prior samples. If the window W(m) contains silence, coefficients of an adaptive filter (52) of the echo canceller (20) are set to silence detection values prior to receipt of a sample at time t(m+1). If the window W(m) does not contain silence and there is no double-talk, the sample obtained at time t(m) is used to update coefficients of the adaptive filter; the adaptive filter as updated generates an echo estimate after a sample is obtained at time t(m+1); and, the echo estimate is used to modify a signal on an outgoing communications path (32).
REFERENCES:
patent: 4582963 (1986-04-01), Danstrom
patent: 4593161 (1986-06-01), Desblache et al.
patent: 4645883 (1987-02-01), Horna et al.
patent: 4736414 (1988-04-01), Montagna et al.
patent: 4751730 (1988-06-01), Galand et al.
patent: 4903247 (1990-02-01), Van Gerwen et al.
patent: 4998241 (1991-03-01), Brox et al.
patent: 5016271 (1991-05-01), Ford
patent: 5263020 (1993-11-01), Yatsuzuka et al.
patent: 5295136 (1994-03-01), Ashley et al.
patent: 5471470 (1995-11-01), Sharma et al.
patent: 5473686 (1995-12-01), Virdee
patent: 5548642 (1996-08-01), Diethorn
patent: 5649011 (1997-07-01), Garofalo et al.
patent: 5687229 (1997-11-01), Sih
patent: 5732134 (1998-03-01), Sih
patent: 5748726 (1998-05-01), Unno
Sondhi and Berkley; "Silencing Echoes on the Telephone Network", Proceedings of the IEEE, vol. 68, No. 8, pp. 948-963, 1990.
Messerschmitt, "Echo Cancellation in Speech and Data Transmission", IEEE Journal on Selected Areas in Communications, vol. 2, No. 2, pp. 283-297, 1984.
Duttweiler and Chen, "A Single-Chip VLSI Echo Canceler", The Bell system Technical Journal, vol. 59, No. 2, pp. 149-160, 1980.
Fertner, U.S. Patent Application Ser. No. 08/679,387, "Frequency Domain Signal Reconstruction in Sampled Digital", filed Jul. 8, 1996.
Nguyen Steven
Pham Chi H.
Telefonaktiebolaget LM Ericsson
LandOfFree
Silence-improved echo canceller does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Silence-improved echo canceller, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Silence-improved echo canceller will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1332126