中文说明：
把信号用数字或符号表示成序列，通过计算机或通用（专用）信号处理设备，用数值计算方法进行各种处理，达到提取有用信息的目的。
English Description：
The signals are expressed into sequences by numbers or symbols, and various processes are carried out by numerical calculation methods through computers or general (special) signal processing equipment, so as to achieve the purpose of extracting useful information