Designing And Implementing Sound Signal Pressing System Based On TMS320C6748

With the development of the digital speech communication, more and more analog speech systems began to upgrade into digital communication device. Because the very limited bandwidth, the digital speech data on the channel must be compacted. Due to the G.723.l codec algorithm has a lower bit rate and good reconstruction speech quality, it is very suitable for multimedia communications in speech coding transmission. In view of the G.723.1 codec algorithm has a high time complexity, the operational ability of DSP must be strong, so we use TMS320C6748 DSP chip as the core.In this paper, the real-time G.723.l speech compression system use TI(Texas Instrument) High-Performance TMS320C6748 DSP chip as the core. The main work includes the following four aspects: The transplantation and optimization of G. 723.1algorithm, the system hardware design and implementation, the system software design and implementation and the evaluation of system voice quality.At first, this paper deeply study the G.723.1 codec algorithm theory. In terms of algorithm optimization, using the DSP internal instruction set and memory optimization methods greatly reduce algorithm running time. In terms of audio data collection, designing the EDMA ping-pong transfer mode, so as to realize the continuous background audio data transmission, effectively reduce the CPU load.Besides, writing serial port driver and designing the communication data frame format, realize the stable G. 723.1 full-duplex communication. At last, it is proved that the real-time speech compression and transmission system is achieved by testing the real-time full duplex system.