Error concealment for speech decoder

A system for improving the quality of a voice call transmitted over a cellular network through a cellular wireless link to a communication device having a voice decoder for generating reconstructed speech, the system comprising:

• a link monitor for monitoring the cellular wireless link to determine a link quality;
• a receiver for receiving a voice packet from the cellular wireless link;
• a determination module coupled to the voice decoder for determining if the voice decoder is a normal speech decoder or a delayed speech decoder;
• and
• an adjustment module, coupled to the voice decoder for:
• dynamically decreasing the latency of the voice call to generate a low-latency voice call by adjusting the voice decoder to said normal speech decoder during silence or background noise periods and thereafter decoding the voice packet immediately, if the voice decoder is said delayed speech decoder and said link quality is above a predetermined threshold;
• and
• dynamically increasing the latency of the voice call to generate a high-latency voice call by adjusting the voice coder to said delayed speech decoder during silence or background noise periods and thereafter delaying the decoding process to perform at least one error correcting technique using newer information contained in speech packets received after a missing frame, if the voice decoder is said normal speech decoder and said link quality is below said predetermined threshold.

A non-transitory computer program product comprising a computer useable medium having computer program logic stored therein, said computer program logic for enabling a computer processing device to improve the quality of a voice call transmitted over a cellular network through a cellular wireless link to a communication device having a voice decoder for generating reconstructed speech, the computer program product comprising:

• code for monitoring the cellular wireless link to determine a link quality;
• code for receiving a voice packet from the cellular wireless link at the decoder;
• code for determining if the voice decoder is a normal speech decoder or a delayed speech decoder;
• code for dynamically decreasing the latency of the voice call to generate a low-latency voice call by adjusting the voice decoder to said normal speech decoder during silence or background noise periods and thereafter decoding the voice packet immediately, if the voice decoder is said delayed speech decoder and said link quality is above a predetermined threshold;
• and
• code for dynamically increasing the latency of the voice call to generate a high-latency voice call by adjusting the voice decoder to said delayed speech decoder during silence or background noise periods and thereafter performing at least one error correcting technique using newer information contained in speech packets received after a missing frame for increasing the quality of the reconstructed speech, if the voice decoder is said normal speech decoder and said link quality is below said predetermined threshold.