(1)建立DQPSK调制和解调 SIMULINK仿真模型，评估其在AWGN信道和瑞利衰落信道下的误码率性能（画出信噪比变化时的误码率曲线）；
(2)基于（1）建立的SIMULINK仿真模型，分别在AWGN信道和瑞利衰落信道下发送一个实际音频文件，在接收端实时播放出来((1) the DQPSK modulation and demodulation SIMULINK simulation model is established to evaluate the bit error rate performance under the AWGN channel and the Rayleigh fading channel (the bit error rate curve when the signal to noise ratio changes).

(2) based on the (1) established SIMULINK simulation model, a real audio file is sent under the AWGN channel and the Rayleigh fading channel respectively, and it is played on the receiving end in real time.)