说明：  通信系统与仿真作业： 1）设计π/4-DPSK或16-QAM调制器仿真程序， 画出时域波形、 正交分量、同相分量波形，眼图，散点图等。 2）利用MATLAB进行DPSK在高斯信道下的BER性能仿真，并将结果与PSK性能进行比较。 3）已知 OFDM的数据传输速率为19.2Kbps， OFDM 符号长度为320，保护间隔为32点，子载波数为128，IFFT/FFT点数为256，载波频率320KHz，调制方案采用QPSK，仿真其在高斯信道下的BER性能。
(Communication systems and simulation tasks: 1) Design π/4-DPSK or 16-QAM modulator simulation program, draw time-domain waveform, quadrature component, in-phase component waveforms, eye diagrams, scatter plots, etc. 2) the use of MATLAB for DPSK in AWGN channel BER performance simulation, and the results are compared with PSK performance. 3) the known OFDM data transmission rate of 19.2Kbps, OFDM symbol length is 320, the guard interval is 32 points, the number of sub-carriers 128, IFFT/FFT points is 256, the carrier frequency is 320KHz, using the modulation scheme QPSK, simulation of the in Gaussian channel BER performance.)