SMVLite: Reduced Complexity Selectable Mode Vocoder

This paper describes the recently developed SMVLite speech codec. SMVLite is the reduced complexity variant of the new 3GPP2 (3rd generation partnership project 2) CDMA standard SMV (selectable mode vocoder). SMV provides superior speech quality at low bit-rates compared to other CDMA codecs. However, its computational complexity is significantly higher than other CDMA standards, thereby rendering it inefficient for real-time implementation. We have developed a lower complexity version of the SMV called SMVLite. SMVLite is bit-stream interoperable with SMV and its voice quality is perceptually equivalent to SMV in all modes & conditions of interest. The computational complexity of SMVLite is 25% lower than SMV. The voice quality equivalence of SMV and SMVLite has been conclusively proven in a formal subjective listening test conducted at Dynastat