XG_FSK.m将fsk信号封装成函数，目的是为了计算相干解调的误码率

函数中，i为噪声功率（程序中，经调整处理，i/2才是噪声功率）

wm设为0。例如，可在commander窗口中调用 XG_FSK(0.02,0)，

0.02代表着功率为0.01的噪声,

就能产生fsk信号的调制、相干解调过程-XG_FSK.m FSK signal encapsulated into function, the purpose is to calculate the coherent demodulation BER function, i is the noise power (the program, after adjustment processing, i/2 is the noise power) WM is set to 0. For example, the commander window the call XG_FSK (0.02,0) 0.02 represents 0.01 power of the noise, can produce the fsk signal modulation, the coherent demodulation process