Aidong N Ning

US Patent:

6968064, Nov 22, 2005

Filed:

Sep 28, 2001

Appl. No.:

09/965959

Inventors:

Aidong Ning - San Jose CA, US

Assignee:

Forgent Networks, Inc. - Austin TX

International Classification:

H04B003/20
H04M009/08

US Classification:

381 66, 37940614, 37940612, 381 943

Abstract:

Disclosed is an apparatus for cancelling far endpoint echo signals in audio signals transmitted from a near endpoint to a far endpoint. In one embodiment, the apparatus includes a near endpoint analysis filter bank operable to divide a near endpoint signal into a plurality of near endpoint subband signals, a far endpoint analysis filter bank operable to divide a far endpoint signal into a plurality of far endpoint subband signals, and a background signal power estimator operable to determine background noise at the near end.

US Patent:

6469732, Oct 22, 2002

Filed:

Nov 6, 1998

Appl. No.:

09/187081

Inventors:

Pi Sheng Chang - San Jose CA
Aidong Ning - Sunnyvale CA
Michael G. Lambert - Austin TX
Wayne J. Haas - Austin TX

Assignee:

VTEL Corporation - Austin TX

International Classification:

H04N 714

US Classification:

348 1408, 348 1409, 348 1401, 381 92

Abstract:

An apparatus and method in a video conference system provides accurate determination of the position of a speaking participant by measuring the difference in arrival times of a sound originating from the speaking participant, using as few as four microphones in a 3-dimensional configuration. In one embodiment, a set of simultaneous equations relating the position of the sound source and each microphone and relating to the distance of each microphone to each other are solved off-line and programmed into a host computer. In one embodiment, the set of simultaneous equations provide multiple solutions and the median of such solutions is picked as the final position. In another embodiment, an average of the multiple solutions are provided as the final position.