用MATLAB实现DPSK编码器功能，该程序对M=8情况的DPSK实现了差分编码-DPSK encoded using MATLAB functions, the program for the case of M = 8 DPSK achieve a differential coding

完成M=4的DPSK通信系统仿真，并求出其相应的误码率、误比特率-M = DPSK complete communication system simulation, and find its corresponding error rate, bit error rate