Study On The ADPCM Encode And Decode System Based On DSP

The essential role of voice encoding technology is to digitize voice communication which will greatly improve the communication technology .So the voice encoding technology is crucial in the whole digital communication system.This article mainly describes the concept and principle of encoding in the first and second chapters. The third chapter mainly describes Adaptive Differential Pulse Code Modulation (ADPCM) algorithm, adaptive quantizing and adaptive predicting algorithm. In the fourth chapter we test and verify ADPCM algorithm in its correction and feasibility based on the system modeling with the SIMULINK, which directs the feasibility and test of system .In the fifth chapter we accomplish the design of hardware circuit based on ADPCM audio encoding algorithm and requirement of system in which we select chips such as DSP (Digital Signal Processor) and Analog to Digital Convert (A/D), we also write some programs by compilation language.This article gives the Simulation model and result of PCM, A-Law PCM, and U-Law PCM with a lot of graphs. From DPCM system, we give ADPCM systematic every subsystem block diagram and SIMULINK emulation model, which makes it very clear to design the whole system based on DSP.