5.6 kbits/s PSI-CELP-PDC HALF-RATE SPEECH CODING STANDARD-

摘要

A Pitch Synchronous Innovation-CELP(PSI-CELP),proposed by NTT DoCoMo in 1993,is adopted as the Japanese half-rate PDC(Personal Digital Cellular)speech codec standard.This algorithm is based on CELP(Code Excited Linear Prediction)with a pitch synchronized excitation source,It uses 3.45 kbit/s out of 5.6 kbit/s for speech coding and the remaining 2.15 kbit/s for error protection.This paper summarizes the standardized PSI-CELP algorithm.The techniques used to improve speech quality,to reduce computational complexity,and to reduce memory requirements are mentioned.A real time operating prototype based on this algorithm is also described.