注释： √CFS(the Continuous-time Fourier Series):连续 时间傅立叶级数 √DFS(the Discrete--time Fourier Series):离散时 间傅立叶级数 *CFT the Continuous -Time Fourier Transforms):连续时间傅立叶变换 DFT the Discrete-Time Fourier Transforms ) 离散时间傅立叶变换 第5章离散时间傅里叶变换 3第5章离散时间傅里叶变换 3 注释: CFS ( the Continuous-time Fourier Series ): 连续 时间傅立叶级数 DFS ( the Discrete-time Fourier Series ): 离散时 间傅立叶级数  CFT ( the Continuous -Time Fourier Transforms ): 连续时间傅立叶变换  DFT ( the Discrete -Time Fourier Transforms ): 离散时间傅立叶变换