G.723.1 Voice Compression Coding To Achieve Real-time On The Tms320vc5501

With the rapid development of communications and internet technology, especially the recent 20 years, speech compressing coding technology has been widely used and plays a very important role in mobile communications, satellite communications, multimedia communications and IP-phone communications. The confilict between user's demand and capability of communication channels is more and more outstanding. How to improve the usage efficiency of resources available is focused,to which people have put much attention.G.723.1 arithmetic is a compressing arithmetic that proposed by ITU-T and applied in speech and other audio frequency signals of low velocity multimedia. The speech coder has two kinds of bit rate, which are 5.3kbps and 6.3kbps,so that it can switches at frame boundaries. This arithmetic provides inspection to silence speech frames and fills in comfortable noise when it is silence. Among the standards which are established using mixed coding technology, G.723.1 has the highest efficiency,and widely used in many fields.But to gain the high quality and low baud rate, G.723.1 pays out the cost,such as the high complex of coding arithmetic,high delay and large storage space.Each of them bings up the difficulties of its real time implementation.At first, from the discrete digital model of the speech generation, the basic of speech encoding technology is briefly introduced in this thesis. Secondly, some key techniques in the linear predictive speech coder of G.723.1 arithmetic are discussed in detail. During the realization of the commendation G.723.1, the hardware platform which is the TMS320VC5501 DSP of TI Inc has been set up. It is introduced in detail in this thesis, too. Thirdly, on the basis of analyzing the capability requirement of G.723.1's real time realization, various methods are used to optimize the original code. Finally, G.723.1 speech coding and decoding are realized on TMS320VC5501 DSP in real time.