Speech data receiver with detection of channel-coding rate

A receiver for channel decoding speech frames, said receiver capable of multiple (M) codec modes, said channel encoded speech frames comprised of an inband bit portion and a speech portion, said receiver comprising:

• an inband bit decoder, the inband bit decoder:
• decoding the inband bit portion of a speech frame to obtain confidence levels associated with each of the M codec modes before a decoding error has been detected;
• ordering the confidence levels from highest to lowest representing a most likely codec mode to a least likely codec mode, respectively, before a decoding error has been detected, based upon a Euclidian distance measure;
• and
• choosing the most likely speech codec mode based on the highest confidence level to decode the speech portion;
• and
• a channel decoder coupled with the inband bit decoder for:
• decoding the speech portion of the received frame using the chosen codec mode, the decoding comprising a recursive convolutional decode;
• performing a frame determination check to determine the quality of the decoded speech frame;
• and
• if the decoded speech frame is determined to be of poor quality, then choosing the next most likely codec mode corresponding to the next highest inband bit decoding confidence level of the confidence levels ordered before a decoding error has been detected and running the channel decoder on the received frame again.

A receiver for channel decoding speech frames, said receiver capable of multiple (M) codec modes, said channel encoded speech frames comprised of an inband bit portion and a speech portion, said receiver comprising:

• an inband bit decoder, the inband bit decoder:
• calculating a plurality of inband decode metrics, one for each codec mode before a decoding error has been detected;
• ordering the inband decode metrics from highest to lowest representing a most likely codec mode to a least likely codec mode, respectively, before a decoding error has been detected, based upon a Euclidian distance measure;
• a channel decoder for:
• partially decoding speech data for each codec mode;
• determining the most likely codec mode based upon the partially decoded speech data and the calculated inband decode metric data;
• and
• resuming decoding of the speech data using the most likely codec mode, the decoding comprising a recursive convolutional decode.