说明：  不用matlab里面的函数，自己写出来的2ASK的仿真程序，加入了白噪声，经过滤波后的波形有些变形，可能是滤波器的原因。仅供参考。
(inside Matlab not a function of their 2ASK written by the simulation program, joined the white noise, filtered waveforms after some deformation, the filter may be reasons. For reference purposes only.)