The Hardware Circuit And Logical Design Of Digital Voice Communication System

The ZigBee technology is designed to provide a low-cost, low power consumption,low-bit rate short distance wireless communication technology. It has been widely used inindustry control, smart home and so on. But it was not designed for voice communicationoriginally. Based on the Zigbee technology, a system model is built to design a hardwareplatform of digital wireless communication.First of all, the author researched the evolution of digital communication, model ofdigital communication, performance index. By comparing several common short rangewireless communication technologies, the Zigbee technology was chosen as a basic of thewhole hardware platform.Subsequently, system technical indicators were determined. On the base of traditionaldigital wireless communication system, the Zigbee communication model was built.Complex and elaborate structures were set up after that.According to the structures of the system, the communication platform based onmicro controller unit was designed. The platform concluded two boards: basebandprocessing board and ZigBee RF board. The function of ZigBee RF board is to keep theinteraction between nodes, while the convertion of analog signal and digital signal, thespeech coding of digital signal were carried out in baseband processing board; Thecommunication of two boards are by SPI interface. After chip analyzing and selection,circuit design, interface design, PCB laying out and debugging, a point to point digitalwireless communication system was designed.Besides, a multi-band excitation speech coding algorithm based on FPGA was triedto replace the function of AMBE2000in order to lower the cost of the whole system. Afterstudying domestic and foreign research of multi-band excitation, the MBE algorithm wassimulated on Matlab platform, and then some parts of the algorithm were completed onFPGA using Verilog HDL.Finally, the communication platforms based on micro controller unit and FPGA wereboth tested. The tests of the platform based on micro controller unit included normalworking test of chips, interface test between chips, system debugging and working test; the tests of the platform based on FPGA included system simulation of each module. Itsuccessfully proved the feasibility of realizing voice communication utilizing ZigBeetechnology.