-based Design And Software Of The Processing System Of The Dsp Wideband Speech

Speech coding systems are generally based on narrowband speech at present, but its frequency is restricted in 200Hz~3400Hz and its sample rate is 8KHz.With the development of the wideband speech, its bandwidth which is from 50Hz to 7KHz causes the quality of speech communication to approach in the feeling of face-to-face conversation, and makes the speech natural, expressive and comfortable.Hence, it's quite significant in researching on wideband speech coding system.In recent 20 years, the DSP and its software development kit has improved greatly, but the price has fallen sharply, thus it has more and more widespread applications now. With the rapid development of DSP technology, it has become a powerful tool in the wideband speech signal processing, which makes it possible to implement the complex algorithms for wideband speech in real time.Now the wideband speech coding standards defined by ITU-T are G.722, G.722.1, G.722.2.G.722 has slight delay and small error rate, but its coding rate is 64, 56 or 48kbit/s. The speech quality of G.722.1 almost equals that of G.722, and the algorithm of G.722.1 is not very complex, whose coding rate is half of G.722.G.722.2 has low coding rate but it's quite complex.Based on the need of the project in practice, G.722.1 is chosed, which is accomplished on TMS320VC5416 produced by Texas Instrument in America.The speech data compressed by TMS320VC5416 is transmited to Embedded PC through PC104 bus, and then is decoded by the decoding software in Embedded PC.The paper consists of the following parts: Firstly, the overview of basic theory of wideband speech coding and G.722.1 coding algorithm is introduced. Secondly, the design of the wideband speech processing system based on DSP is described.Finally, the haredware and software of the system is expatiated, which includes the design of system architecture and its intefaces; the programming and debugging of software in DSP, the driver of the speech gathering card and the interrupt service of TMS320VC5416.