Pulse or digital communications – Receivers – Interference or noise reduction
Reexamination Certificate
2011-05-17
2011-05-17
Payne, David C. (Department: 2611)
Pulse or digital communications
Receivers
Interference or noise reduction
C375S227000, C370S263000, C370S265000, C370S266000, C370S268000, C370S270000
Reexamination Certificate
active
07945006
ABSTRACT:
An apparatus for mixing audio signals in a voice-over-IP teleconferencing environment comprises a preprocessor, a mixing controller, and a mixing processor. The preprocessor is divided into a media parameter estimator and a media preprocessor. The media parameter estimator estimates signal parameters such as signal-to-noise ratios, energy levels, and voice activity (i.e., the presence or absence of voice in the signal), which are used to control how different channels are mixed. The media preprocessor employs signal processing algorithms such as silence suppression, automatic gain control, and noise reduction, so that the quality of the incoming voice streams is optimized. Based on a function of the estimated signal parameters, the mixing controller specifies a particular mixing strategy and the mixing processor mixes the preprocessed voice streams according the strategy provided by the controller.
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Chen Jingdong
Huang Yiteng Arden
Woo Thomas Y
Alcatel-Lucent USA Inc.
Brown Kenneth M.
Guarino Rahel
Payne David C.
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