Politechnika Gdanska

Andrzej Czyzewski

Grzegorz Szwoch

Michal Lech

Cagdas Topcu

Michal Kucewicz

A method of acoustic echo cancellation in the VoIP terminal using processing of the far-end signal with the digital adaptive filter in order to obtain the echo estimate that is subtracted from the microphone signal in which the far-end signal, before it is converted to the analog form and passed to the loudspeaker (), is marked by embedding an encoded digital signature obtained from the signature generator () and then detection of the digital signature is performed in the signal collected by the microphone () and converted to digital form, depending on the result of the digital signature detection, adaptation of the digital adaptive filter () is resumed or stopped. A circuit for acoustic echo cancellation in VoIP terminal contains the digital adaptive filter with the control block situated between the far-end speech signal path and the near-end speech signal path, and the double-talk detector () that comprises the signature generator () connected by the signature encoder () to the signature embedding block () that is situated between the speech decoder () and the digital-to-analog converter () in the far-end speech signal path. The signature generator () is also connected to the signature decoder () which is connected to the output of the analog-to-digital converter () in the near-end speech signal path and the output of the signature decoder () is connected by the decision block () to the control block () of the digital adaptive filter ().

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Gdynia, Poland

Andrzej Czyzewski