Echo cancellation filter

Details Echo cancellation filter Echo cancellation filter

2005-10-11

2005-10-11

Harold, Jefferey F. (Department: 2644)

Telephonic communications

Echo cancellation or suppression

Combined diverse function

C379S406060, C379S406080

Reexamination Certificate

active

06954530

ABSTRACT:
An echo canceler includes an recursive least squares lattice to whiten a far-end signal s1(t) and provide whitened time delays. The echo canceler further decorrelates a microphone signal based on the whitened time delays to reduce echoes of the far-end signal s1(t) that are contained in the microphone signal x2(t). The echo canceler does not use a double-talk detector and avoids all problems inherent with their use. Thus, speaker phones, and other communication devices, can continuously operate in full-duplex mode of operation thereby providing natural conversational hands-free communication.

REFERENCES:
patent: 4131767 (1978-12-01), Weinstein
patent: 4268727 (1981-05-01), Agrawal et al.
patent: 4712235 (1987-12-01), Jones, Jr.
patent: 5295136 (1994-03-01), Ashley et al.
patent: 5390250 (1995-02-01), Janse et al.
patent: RE35574 (1997-07-01), Russell et al.
patent: 5675659 (1997-10-01), Torkkola
patent: 5694474 (1997-12-01), Ngo et al.
patent: 5764753 (1998-06-01), McCaslin et al.
patent: 5909646 (1999-06-01), Deville
patent: 5999956 (1999-12-01), Deville
patent: 6002776 (1999-12-01), Bhadkamkar et al.
patent: 6151397 (2000-11-01), Jackson, Jr. II et al.
patent: 6181794 (2001-01-01), Park et al.
patent: 6272106 (2001-08-01), Kawahara et al.
patent: 6434110 (2002-08-01), Hemkumar
patent: 6507653 (2003-01-01), Romesburg
patent: 6516050 (2003-02-01), Tasaki et al.
patent: 6529606 (2003-03-01), Jackson, Jr. II et al.
patent: 6577675 (2003-06-01), Lindgren et al.
patent: 2002/0114445 (2002-08-01), Benesty et al.
patent: 2002/0181699 (2002-12-01), Pham et al.
patent: 2002/0191779 (2002-12-01), Pham
International Searching Authority, International Search Report for PCT/US04/17897, dated Jan. 3, 2005, 2 pages.
International Searching Authority, Written Opinion of the International Searching Authority for PCT/US04/17897, dated Jan. 3, 2005, 3 pages.
Schobben et al., “A Frequency Domain Blind Signal Separation Method Based on Decorrelation,” IEEE Transactions on Signal Processing, vol. 50, No. 8, Aug. 2002, pp. 1855-1865.
Torkkola, Kari, “Blind Deconvolution, Information Maximization and Recursive Filters,” Motorola, Phoenix Corporate Research Laboratories, 2100 East Elliot Road, MD EL508, Tempe, AZ 85284, USA, 4 pgs.
Torkkola, Kari, “IIR Filters for Blind Deconvolution using Information Maximization,” Motorola, Phoenix Corporate Research Laboratories, 2100 East Elliot Road, MD EL508, Tempe, AZ 85284, USA, 14 pgs.
Feder, et al., “Maximum Likelihood Noise Cancellation Using the EM Algorithm,” IEEE Transactions on Acoustics, Speech, and Signal Processing, vol. 37, No. 2, Feb. 1989, pp. 204-216.
Glentis, et al., “A Unified View—Efficient Least Squares Adaptive Algorithms for FIR Transversal Filtering,” IEEE Signal Processing Magazine, Jul. 1999, pp. 13-41.
Breining, et al., “Acoustic Echo Control—An Application of Very-High-Order Adaptive Filters,” IEEE Signal Processing Magazine, Jul. 1999, pp. 42-69.
“Echo Cancellation Filter” parent patent application and drawings, Inventor Jacob H. Gunther, filed Jul. 9, 2003, pp. 1-31.

Affiliated with

Also associated with

Rating

Echo cancellation filter does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Echo cancellation filter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Echo cancellation filter will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3446778