AMR Codec Mode Selection in TD-SCDMA
Tao Huang, Xiaowen Li, Shitao Li · 2007
Adaptive multi-rate (AMR) codec was standardized for TD-SCDMA by 3GPP (3rd Generation Partnership Project) in 1999. Comparing with previous GSM speech codec, one of AMR code's characteristics is offering adaptive code rates. To AMR codec mode, how to switch from one rate to another according to the radio network condition is a research hotspot in recent years. This paper gives a description about the process of AMR codec mode selection. Applying the MCD (Mel-cepstral distance) measure to the analysis of performances of AMR's eight rates, this paper gives a division to the eight rates. And then, by doing experiments, an ACS with better performance is concluded.