Cheng S Kim

US Patent:

57522294, May 12, 1998

Filed:

Jun 28, 1996

Appl. No.:

8/671746

Inventors:

Donald Lars Duttweiler - Rumson NJ
Toshiro Kawahara - Kanagawa, JP
Cheng Kim - Lincroft NJ
Toshio Miki - Yokohama, JP

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

G10L 918
A04B 323

US Classification:

704270

Abstract:

The detection and cancellation of echo in a communications system is enhanced by taking advantage of the accumulated knowledge relating to the echo path delay that an adaptive filter acquires as a result of its adaptation process. Such knowledge improves significantly the ability of an associated Near-End-Speech (NES) detector to detect for the presence of near end speech.

US Patent:

56688652, Sep 16, 1997

Filed:

Feb 26, 1996

Appl. No.:

8/606934

Inventors:

Donald Lars Duttweiler - Rumson NJ
Cheng Kim - Lincroft NJ
Ying Get Tao - Manalapan NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H04B 323
H04B 320

US Classification:

379410

Abstract:

The detection of echo is enhanced using a coarse near-end speech detector at a Y-side of an echo canceler and using a more accurate near-end speech detector at the E-side of the echo canceler, such that the latter detector uses a representation of far-end speech and a threshold value to determine if the magnitude of the echo canceler output is larger than that of an echo signal only. If it is, and there is an absence of an indication of the presence of near-end speech from the coarse detector, then the more accurate speech detector adjusts the value of the threshold in a first direction, otherwise it adjusts the threshold in a second direction, to more "finely tone" such accuracy.