对实带通和复基带的MQAM的信噪比进行仿真，绘制信噪比曲线、眼图和星座图，在MATLABR2009b上可正常运行-real bandpass and complex baseband simulation of signal to noise ratio of MQAM, including signal to noise ratio curve drawing, eye diagrams and constellation diagrams, can be run in MATLABR2009b