程序是在不同信噪比情况下两跳协作通信系统分别采用AAF和DAF协议时接收端的误码率仿真主函数twohop.m以及一些子函数,假设信道时瑞利信道。S_R\R_D\S_D的传输距离是1米，调制方式是BPSK，信噪比在-15dB-15dB,接收端合并方式为ERC,迭代次数为1000(The program simulates the BER of the main function twohop. m and some sub-functions at the receiver when the two-hop cooperative communication systems adopt AAF and DAF protocols respectively under different signal-to-noise ratios, assuming the Rayleigh channel. The transmission distance of S_RRDS_D is 1 m, the modulation mode is BPSK, the signal-to-noise ratio is -15 dB-15 dB, the receiver combination mode is ERC, and the number of iterations is 1000.)