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, resp