QPSK 在高斯信道下的调制解调的matlab仿真实现，可显示输入数据的波形表示，I支路和Q支路以及调制前、解调后、接收的波形、星座图等-In the Gaussian channel QPSK modulation and demodulation matlab Simulation, the waveform can be displayed, said input data, I branch and Q branch, and before modulation, demodulation, the received waveform, constellation, etc.