The Research Of Using Adaptive Multi-Rate Speech Codec In TD-SCDMA System

Adaptive Multi Rate (AMR) Speech Codec, which is published by 3GPP (3rd generation Partnership Project), is used for speech compressing coding in the W-CDMA system of the 3rd generation mobile communication. TD-SCDMA(Time Division-Synchronous Code Division Multiple Access), Which is proposed by CWTS, has been passed as the 3G wireless communication standard by ITU.AMR speech codec can give a powerful assignment strategy for the signal and channel codec speed services, which can use the wireless resource more flexibly and effectively. Using AMR speech codec in TD-SCDMA system will give the better speech service and more effectively to use the TD-SCDMA resource. This paper will focus on how to use AMR in TD-SCDMA system. We first use MCD (MEL-Cepstral Distance) analyse each mode of AMR speech codec. To design the speed switching strategy, we classified the eight speech modes as three classes. At last we proposed the AMR structure according to the features of TD-SCDMA system. Compare to the AMR in WCDMA system, this structure simplified the terminial's speed-selecting module, which will reduce the complexity of the algorithm and the time delay of the speech.