Echo canceller

The proposed echo canceller comprises: - an adaptive filter for receiving a signal affected by an echo, and for supplying a filtered signal that is an estimate of the echo; - a subtractor for subtracting this estimate from the received signal and supplying a residual signal; - means for detecting (7...

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Bibliographic Details
Main Authors FADILI MOULAY, ZARGOUNI LABIB
Format Patent
LanguageChinese
English
Published 06.03.2013
Subjects
ELECTRIC COMMUNICATION TECHNIQUE
ELECTRICITY
TELEPHONIC COMMUNICATION
TRANSMISSION
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Summary:The proposed echo canceller comprises: - an adaptive filter for receiving a signal affected by an echo, and for supplying a filtered signal that is an estimate of the echo; - a subtractor for subtracting this estimate from the received signal and supplying a residual signal; - means for detecting (7, 8) a ring back tone in said residual signal; - means for blocking (9) the received signal and replacing it by a locally generated ring back tone if a ring back tone is detected in the received signal; - a timer to determine a time period; - and means (11-17) for, during said time period, replacing the residual signal by some synthetic comfort noise when there is no ring back tone.
Bibliography:Application Number: CN201180031900