Matlab仿真通信系统的QPSK调制及相关解调，分别仿真数字信号在AWGN信道和Rayleigh衰落信道中的传输，包含内容：QPSK调制后的波形及其功率谱；AWGN信道输出波形及其功率谱；信号在Rayleigh信道之前与之后的星座图；6.用半波分析法仿真在AWGN信道与Rayleigh信道下的传输差错特性-Matlab simulation of QPSK modulation and demodulation of the communication system, are simulated digital signal transmission in AWGN and Rayleigh fading channels, with content: QPSK modulation waveform and power spectrum　AWGN channel output waveform and power spectrum　signal in Rayleigh channel before and after the constellation diagram　6. using half-wave analysis simulation characteristics of AWGN channel and Rayleigh channel transmission errors