The Study Of G.729 Speech Coding Algorithm And It's Optimal DSP Implementation

With the rapid progress of morden mobile communication, the bandwidth utilization and speech quality are becoming the main problem. The valid approach to solve this problem is low rate, delay, loss and high quality codec. To meet such requirement, ITU has enacted G.729 protocol in 1996. G.729 is based on CS-ACELP at 8kbit/s, and has the advantage of low delay, high speech quality. It can be widely used in the field of individual mobile communication, multimedia communication, IP phone, satellite communication, ISDN and so on. It is recommended to the telecom department all over the world by the ITU, but it is difficult to realize in real time because of the high algorithmic complexity.With the rapidly developing of DSP technology in recent decades, the computational capability of the chip is gradually improved, and the chip cost is reduced, so the DSP has become the main tool in the field of speech signal processing guadually, and make it become possible to realize the more complex codec algorithm in a single chip.In this paper, based on grasping the principle of G.729, hardware design and several software optimization techniques are presented for efficient implementation of G.729 standard. The main work is follow:(1) Based on the principle of G.729 and plenty of literatures, the algorithm details have been researched deeply.(2) According to the requirement of memory and running speed for G.729 implementation, the hardware platform is designed.(3) After the analysising of G.729 flow, the peak value of calculation is estimated. For efficient implementation of G.729, several optimization techniques are presented on the level of C language, assembly and algorithmespecially the last two.