本文共包括七个部分:①用 DFT 法实现数字滤波的基本原理,②短序列信号的滤波,DFT 法与卷积法的比较,③滤波器冲击响应的截取,各种常用窗函数,④长序列信号的滤波,⑤求系统的传递函数,多次平均法,⑥LFM 信号的脉冲压缩,旁瓣的抑制,⑦窄带高频信号的滤波。 This paper consists of seven parts: ①DFT method to achieve the basic principles of digital filtering, ② short sequence signal filtering, DFT method and convolution comparison, ③ filter impulse response interception, a variety of commonly used window functions, ④ long Sequence signal filtering, ⑤ seeking the system transfer function, multiple averaging method, ⑥ LFM pulse compression, sidelobe suppression, ⑦ narrowband high-frequency signal filtering.