METHOD AND APPARATUS FOR PCM CODEC SAMPLE CALIBRATION OF GSM VOCODER SYBSYSTEM IN A MOBILE COMMUNICATION SYSTEM

摘要

A method and an apparatus for correcting a PCM(Pulse Code Modulation) codec sample of a GSM(Global System for Mobile Communication) vocoder subsystem are provided to improve the sound quality of GSM system terminal by correcting the number of PCM codec samples based on a GSM system frame and normally operating a vocoder. A method for correcting a PCM codec sample of a GSM vocoder subsystem includes the steps of: storing the PCM samples from a codec in a buffer at an interval of the predetermined time in case of up-link to encode the PCM samples based on a GSM frame unit; performing the encoding process with the samples when the samples of the frame unit time are filled in the buffer, and performing the transmission of encoded samples to a GSM modem; and storing the PCM samples generated by decoding a packet transmitted from the GSM modem in case of down-link, increasing a pointer every predetermined time, and outputting the samples to the PCM codec one by one.