滤波器设计 　　　产生一个连续信号，包含低频，中频，高频分量，对其进行采样，进行频谱分析，分别设计低通，带通，高通滤波器对信号进行滤波处理，观察滤波前后信号的频谱。-The filter is designed to generate a continuous signal containing the low, mid, and high frequency components, to be sampled, for spectral analysis, respectively, to

子带编码是一种以信号频谱为依据的波形编码方法，首先用一组带通滤波器将输入信号按频谱分开，然后让每路子信号通过各自的自适应PCM编码器（ADPCM）编码，经过分接和解码再复合成原始信号。-In sub-band coding is a waveform signal based on the spectrum coding method using a first set of band pass filters to separate an input signal spectrum, and