不考虑多径干扰时在高斯白噪声和瑞利衰落信道条件下QPSK的调制解调过程，

并采用准分析法完成误码性能的计算。仿真过程包括仿真信号产成，滤波器设置，QPSK调制，加入高斯白噪声，通过锐利信道衰落，QPSK解调，误码率计算等几部分-Not consider multi-path interference at the white Gaussian noise and Rayleigh fading channel under the conditions of the QPSK modulation and demodulation process and the use of quasi-analysis method to complete the calculation of BER. The simulation process includes the middle class into a simulation signal, filter settings, QPSK modulation, by adding Gaussian white noise, through the sharp decline in channel, QPSK demodulation, bit error rate calculation and other parts