Abstract: To address issues with present echo gate control, a method and apparatus for more intelligently operating an echo gate is described herein. In particular, the decision of whether to mute an uplink signal, or not, is formulated herein as primarily a perceptual decision based on an appropriate analysis of the perceptual interaction of the current residual echo and the current near-end signal(s). By doing so, the application of muting through an echo gate may be minimized and/or more appropriately engaged. This will lead to fewer dropouts and muting of speech onsets and offsets 1) during periods such as double-talk or 2) during periods of downlink playback in the presence of low near-end signal levels, two cases of particular importance.

Abstract: A conference system is described that transfers audio signals/streams between a near-end computing system and a far-end computing system. The near-end system may produce a plurality of microphone beams capturing various areas of the near-end. The beams may include primary beams directed at targets of interest and secondary beams focused on sound sources away from the targets of interest. The secondary beams may be selectively used as de-correlating signals for de-correlating the primary beams. The mixing may be made using a scale factor to produce a new primary beam. When the new beam does not provide significant de-correlation and the original raw primary beams are already sufficiently de-correlated, the original raw primary beams may be transmitted to the far-end system.

Abstract: A system and method is described for estimating residual echo and performing residual echo suppression on a signal. In particular, the system and method described herein: 1) provides a more accurate coherence-based approach where the sub-band nature of coherence-based residual echo estimation is leveraged using sub-band-based coherence measures and upper-bound envelopes to guide residual echo estimates; 2) provides joint estimation of the residual echo and a background stationary noise-floor; 3) provides more accurate residual echo estimation by combining the above two measures with information on near-end activity to selectively adjust the residual-echo estimation in sub-bands; and 4) provides improved control of near-end distortion by leveraging the noise-floor estimate and the internally calculated signal-to-echo ratios as additional guides/limits to help balance, flexibly, and as needed, near-end distortion with residual echo suppression.

Abstract: A system and method is described for estimating residual echo and performing residual echo suppression on a signal. In particular, the system and method described herein: 1) provides a more accurate coherence-based approach where the sub-band nature of coherence-based residual echo estimation is leveraged using sub-band-based coherence measures and upper-bound envelopes to guide residual echo estimates; 2) provides joint estimation of the residual echo and a background stationary noise-floor; 3) provides more accurate residual echo estimation by combining the above two measures with information on near-end activity to selectively adjust the residual-echo estimation in sub-bands; and 4) provides improved control of near-end distortion by leveraging the noise-floor estimate and the internally calculated signal-to-echo ratios as additional guides/limits to help balance, flexibly, and as needed, near-end distortion with residual echo suppression.

Abstract: To address issues with present echo gate control, a method and apparatus for more intelligently operating an echo gate is described herein. In particular, the decision of whether to mute an uplink signal, or not, is formulated herein as primarily a perceptual decision based on an appropriate analysis of the perceptual interaction of the current residual echo and the current near-end signal(s). By doing so, the application of muting through an echo gate may be minimized and/or more appropriately engaged. This will lead to fewer dropouts and muting of speech onsets and offsets 1) during periods such as double-talk or 2) during periods of downlink playback in the presence of low near-end signal levels, two cases of particular importance.

Abstract: A WLAN system adapted to apply QoS differentiation to a media stream to be transmitted from a transmitting station (STA) to a receiving STA of that system. The transmitting STA processes the media stream to generate a base sub-stream and one or more enhancement sub-streams for subsequent transmission over a wireless communication channel and assigns different priorities to different sub-streams. Depending on the channel conditions, the transmitting STA may select to discard, without transmission, portions of data from enhancement sub-streams. The selection process is based on the assigned priority and operates to preserve as much of relatively high-priority data as possible. The receiving STA then processes the received data to generate a reconstructed media stream, which provides signal quality equal to or better than the signal quality supported by the base sub-stream.

Abstract: Source-coded information from a multi-mode source encoder is channel coded for transmission in a communication system. A multi-mode channel encoder associates a different channel coding error protection profile with each of the modes of the multi-mode source encoder. The channel encoder determines a mode used by the multi-mode source encoder to source code a given frame or other designated portion of the information, and channel codes the source-coded portion of the information utilizing an error protection profile identified at least in part based on the determined mode. A multi-mode channel decoder is operative to hypothesize that a particular one of the modes of the multi-mode source encoder was used to source code the designated portion of the information.

Abstract: Source-coded information from a multi-mode source encoder is channel coded for transmission in a communication system. A multi-mode channel encoder associates a different channel coding error protection profile with each of the modes of the multi-mode source encoder. The channel encoder determines a mode used by the multi-mode source encoder to source code a given frame or other designated portion of the information, and channel codes the source-coded portion of the information utilizing an error protection profile identified at least in part based on the determined mode. A multi-mode channel decoder is operative to hypothesize that a particular one of the modes of the multi-mode source encoder was used to source code the designated portion of the information.