Wireless Voice Communication System, Qpsk Modulation And Demodulation,

The project is a part of the wireless speech system.The aim of the project is to implement the π/4-DQPSK modem.The bite rate is 8Kb/s and the intermediate frequency is 455KHz.The paper introduces the basic theory ofπ/4-DQPSK at first .Then analyzes the structure and elements. Discribes the process of designing and simulating ofπ/4-DQPSK modulating and demodulating algorithm with Matlab. Discribes the frame of software and presents the simulating waveform.. At last, presents the scheme of realizing the hardware platform and debugging method.The π/4-DQPSK modem completes the designing requirement.When debugging with the speech compression system ,it works well and the voice is clear.It proves thatπ/4-DQPSK modem can complete modulating and demodulating task of the wireless speech system.What I have done in this subject include:Consulting the reference to learn the structure and elements.Determining the designing scheme .Designing and simulating ofπ/4-DQPSK modulating and demodulating algorithm with Matlab.π/4-DQPSK modulating software designing.1bit demodulating software designingSimulating the whole software and analyzing the simulating results.Designing and debugging the hardware of the system.Debugging the system.