CXY 可用来验证：

1、不同FFT点数的结果*2/M 真实幅度（电压值）（第一二行图）

2、验证计算Ps,Pn及SNR的方法，通过构造加AWG噪声的信号来印证（第二三行图）

3、对比N在整周波和非整周波情况下的通过SNR观察频谱泄露效应（第三行图）-

　CXY can be used to verify:

　1, the result of different FFT points* 2/M　 true amplitude (voltage value) (first two lines)

　2, verify the calculation of Ps, Pn and SNR method, by constructing the AWG noise signal to confirm (the second three lines)

　3, contrast N observed in the case of full and non-circular waves through SNR spectrum leakage effect (the third line)