中文说明：该程序给出了一个4*4_MIMO的实现，包含802.11n信道模型和AWGN信道模型，同时给出了在此模型下的时频估计计算，最后得到信噪比与误码率之间的关系曲线图。
English Description：
The program presented an implementation of 4*4_MIMO, and contains the 802.11n channel and AWGN channel model and frequency estimation in this model is given, and finally the signal to noise ratio-BER curve.