REAL-TIME IMPLEMENTATION OF G.723.1 SPEECH CODER USING TMS320VC5402 DSP CHIP

A. R. ZOLGHADR ASLI, Ph.D., Dept. of Electrical Engineering, School of Engineering, Shiraz University, Shiraz, I. R. of Iran

E. GOODARZI, M.S.,Graduate, Dept. of Electrical Engineering, School of Engineering, Shiraz University,Shiraz, I. R. of Iran

M. MOOSAVINEZHAD, M.S.,Iran Telecommunication, Research Center (ITRC), Tehran, I.R. of Iran

Abstract

This paper presents a full duplex, real time implementation of ITU-T G.723.1 [7,8] speech coder using the TMS320C5402 DSP chip which is based on a 16 bit fixed-point architecture. An optimization method is proposed in order to reduce the total necessary cycle time consumed in real-time implementation. The Multi-Pulse Maximum Likelihood Quantization (MP-MLQ) excitation search block which is the most computation-intensive block in the coder is restructured to reduce the algorithmic redundancy. In addition, efficient filtering methods and memory management are used for further optimization. The bit-exact verification with the ITU test vectors and performance evaluation aspects are also discussed in this paper.

Keywords - ITU-T G.723.1 Speech Coder, Real-Time Implementation, Acelp Excitation, Mp-Mlq Excitation.

email: zolghadr@shirazu.ac.ir