Abstract:
In the last 15 years, due to the expansion of the mobile telephony, but not only, efficient, low cost and low power compression methods for speech signals have been developed. At this moment, many standards for vocoders are implemented, the most used beeing GSM 723 or GSM 728. Most of them have as basic principle the linear prediction coding, which consists basically in coding a frame of typically 20ms of speech by using an MA predictor. This paper aims to improve the quality of a low bit rate vocoder (LPC10 like) by accurately finding the pitch.