Telephonic communications – Diagnostic testing – malfunction indication – or electrical... – Of hybrid or echo suppressor or canceller
Reexamination Certificate
2006-02-14
2006-02-14
Nguyen, Duc (Department: 2643)
Telephonic communications
Diagnostic testing, malfunction indication, or electrical...
Of hybrid or echo suppressor or canceller
C379S406010, C379S392000
Reexamination Certificate
active
06999560
ABSTRACT:
A test system measures performance of telephone network echo cancellers using a primary criterion of estimated user annoyance due to audible returned echo. The invention generates live telephone calls, uses real speech samples as stimulus signals and provides tail-circuit emulation using actual measured telephone tail-circuit impulse responses. These features provide better ‘real-life’ test conditions for the echo canceller system under test than current ITU standard test methods. Two methods are employed for echo canceller performance evaluation via metrics of estimated user annoyance due to echo. Energy-based method employs point-by-point comparison of talker speech and talker echo signal energy envelopes and uses variable energy thresholds for estimation of echo audibility. A perceptual-model based method uses a Perceptual Speech Distortion Metric (PSDM), such as ITU P.861, in an unique configuration to estimate user annoyance due to audible echo. Echo canceller performance is tested under both single-talk and double-talk conditions. Innovative application of the PSDM method in double-talk tests allow estimation of quality of received double-talk speech.
REFERENCES:
patent: 3637954 (1972-01-01), Anderson et al.
patent: 4363122 (1982-12-01), Black et al.
patent: 4449231 (1984-05-01), Chytil
patent: 4727566 (1988-02-01), Dahlqvist
patent: 4918685 (1990-04-01), Tol et al.
patent: 5008923 (1991-04-01), Kitamura et al.
patent: 5303228 (1994-04-01), Tzeng
patent: 5600718 (1997-02-01), Dent et al.
patent: 5621854 (1997-04-01), Hollier
patent: 5633936 (1997-05-01), Oh
patent: 5680450 (1997-10-01), Dent et al.
patent: 5867574 (1999-02-01), Eryilmaz
patent: 6122531 (2000-09-01), Nicholls et al.
patent: 6275794 (2001-08-01), Benyassine et al.
patent: 6282176 (2001-08-01), Hemkumar
Connor Kevin J.
Jagadeesan Ramanathan T.
Knappe Michael E.
Cisco Technology Inc.
Marger Johnson & McCollom PC
Nguyen Duc
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