Bit error management methods for wireless audio communication channels

Abstract

Systems and methods are described for managing bit errors present in an encoded bit stream representative of a portion of an audio signal, wherein the encoded bit stream is received via a channel in a wireless communications system. The channel may comprise, for example, a Synchronous Connection-Oriented (SCO) channel or an Extended SCO (eSCO) channel in a Bluetooth® wireless communications system.

What is claimed is: 
     
         1 . A method for managing bit-errors present in an audio-encoded bit stream representative of a portion of an audio signal, comprising:
 receiving the audio-encoded bit stream over a communication channel;   analyzing the audio-encoded bit stream to estimate a distribution, extent and/or location of bit errors in the audio-encoded bit stream;   when bit errors are detected in the audio-encoded bit stream, selecting a first one of a plurality of means for producing a series of digital audio samples representative of the portion of the audio signal based on determining that there is at least one of a first estimated distribution, extent and location of bit errors in the audio-encoded bit stream and selecting a second one of the plurality of means for producing the series of digital audio samples representative of the portion of the audio signal based on determining that there is at least one of a second estimated distribution, extent and location of bit errors in the audio-encoded bit stream; and   converting the series of digital audio samples produced by the selected means into a form suitable for playback to a user.   
     
     
         2 . The method of  claim 1 , wherein receiving the audio-encoded bit stream over the communication channel comprises:
 receiving the audio-encoded bit stream as part of a packet transmitted over a Synchronous Connection-Oriented (SCO) communication channel.   
     
     
         3 . The method of  claim 1 , further comprising:
 generating one or more indicators that indicate a quality of a wireless link over which the communication channel was established;   wherein the selecting step comprises selecting the first or second one of the plurality of means for producing the series of digital audio samples representative of the portion of the audio signal based on determining that there is at least one of the first or second estimated distribution, extent and/or location of the bit errors and the indicator(s).   
     
     
         4 . The method of  claim 1 , wherein the selecting step comprises selecting the first or second one of the plurality of means for producing the series of digital audio samples representative of the portion of the audio signal based on determining that there is at least one of the first or second estimated distribution, extent and/or location of the bit errors and an analysis of one or more previously-received portions of the audio signal. 
     
     
         5 . The method of  claim 1 , wherein selecting the first or second one of the plurality of means for producing the series of digital audio samples representative of the portion of the audio signal comprises:
 selecting a packet loss concealment (PLC) block to produce the series of digital audio samples.   
     
     
         6 . The method of  claim 1 , wherein selecting the first or second one of the plurality of means for producing the series of digital audio samples representative of the portion of the audio signal comprises:
 selecting an audio decoder that decodes the audio-encoded bit stream to produce the series of digital audio samples.   
     
     
         7 . The method of  claim 1 , wherein selecting the first or second one of the plurality of means for producing the series of digital audio samples representative of the portion of the audio signal comprises:
 selecting an audio decoder to decode a first portion of the audio-encoded bit stream to produce a first portion of the series of digital audio samples; and   selecting a packet loss concealment (PLC) block to produce a second portion of the series of digital audio samples.   
     
     
         8 . A system, comprising:
 a demodulator/channel decoder configured to receive a modulated carrier signal from an antenna and to generate an audio-encoded bit stream representative of a portion of an audio signal therefrom;   a bit error detection and concealment block configured
 to analyze the audio-encoded bit stream to estimate at least one of a distribution, extent and/or location of bit errors in the audio-encoded bit stream, and 
 to select a packet loss concealment (PLC) block and/or an audio decoder for producing a series of digital audio samples representative of the portion of the audio signal based on at least one of the estimated distribution, extent and location of bit errors in the audio-encoded bit stream; and 
   a digital to analog converter configured to convert the series of digital audio samples into an analog audio signal suitable for playback to a user.   
     
     
         9 . The system of  claim 8 , wherein the modulated carrier signal is received over a Synchronous Connection-Oriented (SCO) communication channel. 
     
     
         10 . The system of  claim 8 , wherein the audio decoder comprises a Continuously Variable Slope Delta Modulation (CVSD) decoder. 
     
     
         11 . The system of  claim 8 , wherein the demodulator/channel decoder is further configured to generate one or more indicators that indicate a quality of a wireless link over which the communication channel was established; and
 wherein the bit error detection and concealment block is configured to select the packet loss concealment (PLC) block and/or the audio decoder for producing the series of digital audio samples representative of the portion of the audio signal based on the at least one of the estimated distribution, extent and/or location of bit errors in the audio-encoded bit stream and the indicator(s).   
     
     
         12 . The system of  claim 8 , wherein the bit error detection and concealment block is configured to select the packet loss concealment (PLC) block and/or the audio decoder for producing the series of digital audio samples representative of the portion of the audio signal based on the at least one of the estimated distribution, extent and/or location of bit errors in the audio-encoded bit stream and an analysis of one or more of the previously-received portions of the audio signal. 
     
     
         13 . The system of  claim 8 , wherein the bit error detection and concealment block is configured to select the audio decoder to decode a first portion of the audio-encoded bit stream to produce a first portion of the series of digital audio samples and to select the packet loss concealment (PLC) block to produce a second portion of the series of digital audio samples. 
     
     
         14 . A method for managing bit-errors present in an audio-encoded bit stream representative of a portion of an audio signal, comprising:
 receiving the audio-encoded bit stream over a communication channel;   generating a data cyclic redundancy check (CRC) indicator associated with the audio-encoded bit stream;   determining if bit errors are present in the audio-encoded bit stream based on the data CRC indicator; and   responsive to determining that bit errors are present in the audio-encoded bit stream based on the data CRC indicator:
 analyzing the audio-encoded bit stream to estimate a distribution, extent and/or location of bit errors in the audio-encoded bit stream, 
 selecting a first one of a plurality of means for producing a series of digital audio samples representative of the portion of the audio signal based on determining that there is at least one of a first estimated distribution, extent and/or location of bit errors in the audio-encoded bit stream, and selecting a second one of the plurality of means for producing the series of digital audio samples representative of the portion of the audio signal based on determining that there is at least one of a second estimated distribution, extent and location of bit errors in the audio-encoded bit stream, and 
   converting the series of digital audio samples produced by the selected means into a form suitable for playback to a user.   
     
     
         15 . The method of  claim 14 , wherein receiving the audio-encoded bit stream over a communication channel comprises:
 receiving the audio-encoded bit stream as part of a packet transmitted over an Extended Synchronous Connection-Oriented (eSCO) communication channel.   
     
     
         16 . The method of  claim 14 , wherein selecting the means for producing the series of digital audio samples representative of the portion of the audio signal comprises:
 selecting a packet loss concealment (PLC) block to produce the series of digital audio samples.   
     
     
         17 . The method of  claim 14 , wherein selecting the means for producing the series of digital audio samples representative of the portion of the audio signal comprises:
 selecting an audio decoder that decodes the audio-encoded bit stream to produce the series of digital audio samples.   
     
     
         18 . The method of  claim 14 , wherein selecting the means for producing the series of digital audio samples representative of the portion of the audio signal comprises:
 selecting an audio decoder to decode a first portion of the audio-encoded bit stream to produce a first portion of the series of digital audio samples; and   selecting a packet loss concealment (PLC) block to produce a second portion of the series of digital audio samples.   
     
     
         19 . The method of  claim 14 , further comprising:
 generating one or more indicators that indicate a quality of a wireless link over which the communication channel was established;   wherein the selecting step comprises selecting the first or second one of the plurality of means for producing the series of digital audio samples representative of the portion of the audio signal based on at least the estimated distribution, extent and/or location of the bit errors and the indicator(s).   
     
     
         20 . The method of  claim 14 , wherein the selecting step comprises selecting the first or second one of the plurality means for producing the series of digital audio samples representative of the portion of the audio signal based on determining that there is at least one of the first or second estimated distribution, extent and/or location of the bit errors and an analysis of one or more previously-received portions of the audio signal.