中文说明：
本例用matlab语言实现了4QPSK的编解码及通过awgn信道的仿真。采用蒙特卡罗仿真法，得到误码性能，绘制曲线。可用于算法研究或课程学习。
English Description：
This example uses MATLAB language to realize the coding and decoding of 4qpsk and the simulation through AWGN channel. Using Monte Carlo simulation method, the bit error performance is obtained and the curve is drawn. It can be used for algorithm research or course learning