包括调制，解调，信噪比计算，小波包分析提取振动信号中的特征频率，二维声子晶体FDTD方法计算禁带宽度的例子。- Includes the modulation, demodulation, signal to noise ratio calculation, Wavelet packet analysis to extract vibration signal characteristic frequency, Dimensional phononic crystals FDTD method