VOICE ACTIVITY DETECTION (VAD) DEPENDENT RETRANSMISSION SCHEME FOR WIRELESS COMMUNICATION SYSTEMS
First Claim
1. A method for selectively issuing retransmission requests by a terminal in a wireless communication system, comprising:
- determining whether a packet received over a wireless channel from a remote terminal and carrying encoded audio samples representative of a frame of an audio signal is deemed bad;
responsive to determining that the packet is deemed bad;
determining whether voice activity has been detected in the audio signal based on an analysis of at least one previously-received frame of the audio signal; and
generating a retransmission request for the packet for transmission to the remote terminal responsive to determining that voice activity has been detected.
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0 Petitions
Accused Products
Abstract
A voice activity detection (VAD) dependent retransmission scheme is described that mitigates the effect of packet loss on an audio signal transmitted between terminals in a wireless communication system in a manner that is generally more robust than conventional state-of-the art packet loss concealment algorithms but that consumes less terminal power as compared to conventional retransmission schemes. In one implementation, this is achieved by allowing retransmissions to be requested by a terminal only when a packet received by the terminal is deemed bad and when a portion of an audio signal currently being received by the terminal is deemed to comprise active speech. In other implementations, the processing of retransmission requests received by a terminal is inhibited or turned off entirely during periods when a portion of an audio signal currently being transmitted by the terminal is deemed not to comprise active speech.
9 Citations
25 Claims
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1. A method for selectively issuing retransmission requests by a terminal in a wireless communication system, comprising:
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determining whether a packet received over a wireless channel from a remote terminal and carrying encoded audio samples representative of a frame of an audio signal is deemed bad; responsive to determining that the packet is deemed bad; determining whether voice activity has been detected in the audio signal based on an analysis of at least one previously-received frame of the audio signal; and generating a retransmission request for the packet for transmission to the remote terminal responsive to determining that voice activity has been detected. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A terminal for use in a wireless communication system, comprising:
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a demodulator/channel decoder configured to determine whether a packet received over a wireless channel from a remote terminal and carrying encoded audio samples representative of a frame of an audio signal is deemed bad; a voice activity detector configured to determine whether voice activity has been detected in the audio signal based on an analysis of at least one previously-received frame of the audio signal; and a retransmission request generator connected to the demodulator/channel decoder and the voice activity detector, the retransmission request generator configured to generate a retransmission request for the packet for transmission to the remote terminal responsive to a determination by the demodulator/channel decoder that the packet is deemed bad and to a determination by the voice activity detector that voice activity has been detected in the audio signal. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
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15. A method for selectively processing retransmission requests received by a terminal in a wireless communication system, comprising:
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receiving a retransmission request from a remote terminal for a packet previously transmitted to the remote terminal over a wireless channel, wherein the packet carried encoded audio samples representative of a frame of an audio signal; responsive to receiving the retransmission request; determining whether voice activity has been detected in the audio signal based on an analysis of at least one previously-processed frame of the audio signal; and processing the retransmission request responsive to determining that voice activity has been detected, wherein processing the retransmission request includes retransmitting the packet to the remote terminal. - View Dependent Claims (16, 17, 18)
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19. A terminal for use in a wireless communication system, comprising:
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a demodulator/channel decoder configured to receive a retransmission request from a remote terminal for a packet previously transmitted to the remote terminal over a wireless channel, wherein the packet carried encoded audio samples representative of a frame of an audio signal; a voice activity detector configured to determine whether voice activity has been detected in the audio signal based on an analysis of at least one previously-processed frame of the audio signal; and a retransmission request processor connected to the demodulator/channel decoder and the voice activity detector, the retransmission request processor configured to receive the retransmission request from the demodulator/channel decoder and to process the retransmission request responsive to a determination by the voice activity detector that voice activity has been detected in the audio signal, wherein processing the retransmission request includes retransmitting the packet to the remote terminal. - View Dependent Claims (20, 21, 22, 23, 24)
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25. A method for managing the processing of retransmission requests by a terminal in a wireless communication system, comprising:
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monitoring an audio signal to be transmitted to a remote terminal over a wireless channel to determine whether voice activity has been detected in the audio signal; and turning off an antenna that monitors the wireless channel for retransmission requests from the remote terminal and/or logic that demodulates/decodes such retransmission requests responsive to determining that no voice activity has been detected in the audio signal.
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Specification