Method and apparatus for detecting bad data packets received by a mobile telephone using decoded speech parameters

A mobile telephone comprising:

• means for receiving variable rate packets containing received digitized speech parameters;
• means for determining the frame rate of each packet;
• means for performing error detection on said packets to identify transmission errors therein or to determine whether the packet is subject to a frame rate detection error;
• frame erasure means for eliminating packets found to contain transmission errors or found to be subject to a frame rate detection error;
• a decoder, responsive to said means for determining the rate of each packet, tat generates processed speech parameters from the received speech parameters from packets not eliminated by the frame erasure means, the processed speech parameters being based at least in part on the frame rate of the packet;
• a comparator that compares the processed speech parameters with at least one preselected range of acceptable speech parameters, the comparing being based at least in part on a rate of change of the processed speech parameters;
• and
• means for applying packets having processed speech parameters found to deviate from said preselected ranges of acceptable speech parameters to said frame erasure means.

A mobile telephone comprising:

• a receiver for outputting packets containing received digitized speech parameters;
• a frame rate detection unit for determining the frame rate for each packet;
• an error detection unit for performing error detection on said packets to identify transmission errors therein or to determine whether the packet is subject to a frame rate detection error;
• a frame erasure unit for eliminating packets found to contain transmission errors or found to be subject to a frame rate detection error;
• a decoder, responsive to said frame rate detection unit, that generates processed speech parameters from the received speech parameters from packets not eliminated by the frame erasure unit, the processed speech parameters being based at least in part on the detected frame rate of the packet;
• a comparator that compares the processed speech parameters with at least one preselected range of acceptable speech parameters, the comparing being based at least in part on a rate of change of the processed speech parameters;
• and
• means for applying packets having processed speech parameters found to deviate from said preselected ranges of acceptable speech parameters to the frame erasure unit.

A signal reception method for use in a mobile telephone system, said method comprising the steps of:

• receiving a digitized signal containing received speech parameters representative of speech;
• decoding, responsive to a detected bit rate, the received speech parameters to generate processed speech parameters, the processed speech parameters being based at least in part on the detected bit rate;
• comparing the processed speech parameters with at least one predetermined range of acceptable speech parameters to identify and discard atypical speech parameters outside of said predetermined ranges, said comparing being based at least in part on a rate of change of the processed speech parameters;
• and
• outputting, through a speaker, an audio signal associated with processed speech parameters lying within said predetermined ranges.

A method for use in a mobile telephone comprising the steps of:

• receiving variable rate packets containing received digitized speech parameters;
• determining the frame rate of each packet;
• performing error detection on frames of said packets to identify transmission errors therein or to determine whether the packet is subject to a frame rate detection error;
• eliminating frames found to contain transmission errors or found to be subject to a frame rate detection error;
• decoding, responsive to said step of determining the frame rate of each packet, the received speech parameters from frames not eliminated by the step of eliminating frames to thereby generate processed speech parameters, the processed speech parameters being based at least in part on the frame rate of the packet;
• comparing the processed speech parameters with at least one preselected range of acceptable speech parameters, said comparing being based at least in part on a rate of change of the processed speech parameters;
• and eliminating frames having processed speech parameters found to deviate from said preselected ranges of acceptable speech parameters.