说明：  QPSK调制后产生QPSK信号，QPSK信号分别通过AWGN信道、Rayleigh衰减信道和Rician衰减信道，分别通过QPSK解调出数字信号，通过输入与输出数字信号的对比计算出仿真过程中的传输误比率，并将其与各衰减信道的理论误比率进行对比
(Generate QPSK signal QPSK modulation, QPSK signals through AWGN channel, Rayleigh fading channel and Rician fading channel, respectively, through the QPSK demodulation of digital signals by comparing input and output digital signals to calculate the simulation process of transmission error rate, and to compare with the theoretical error rate for each decay channel)