8.1 representation of periodic sequences:the discrete fourier series 8.2 the fourier transform of periodic signals 8.3 properties of the discrete fourier series 8.4 fourier representation of finite-duration sequences: Definition of the discrete fourier transform 8.5 sampling the fourier transform(point of sampling) 8.6 properties of the fourier transform 8.7 linear convolution using the discrete fourier transform 8.8 the discrete cosine transform(DCT)

◆8.0 Introduction ◆8.1 Representation of Periodic Sequence: the Discrete Fourier Series ◆8.2 Properties of the Discrete Fourier Series ◆8.3 The Fourier Transform of Periodic Signal ◆8.4 Sampling the Fourier Transform ◆8.5 Fourier Representation of Finite-Duration Sequence: the Discrete Fourier Transform ◆8.6 Properties of the Discrete Fourier Transform ◆8.7 Linear Convolution using the Discrete Fourier Transform ◆8.8 the discrete cosine transform (DCT)

◆8.0 Introduction ◆8.1 Representation of Periodic Sequence: the Discrete Fourier Series ◆8.2 Properties of the Discrete Fourier Series ◆8.3 The Fourier Transform of Periodic Signal ◆8.4 Sampling the Fourier Transform ◆8.5 Fourier Representation of Finite-Duration Sequence: the Discrete Fourier Transform ◆8.6 Properties of the Discrete Fourier Transform ◆8.7 Linear Convolution using the Discrete Fourier Transform ◆8.8 the discrete cosine transform (DCT)

◆8.0 Introduction ◆8.1 Representation of Periodic Sequence: the Discrete Fourier Series ◆8.2 Properties of the Discrete Fourier Series ◆8.3 The Fourier Transform of Periodic Signal ◆8.4 Sampling the Fourier Transform ◆8.5 Fourier Representation of Finite-Duration Sequence: the Discrete Fourier Transform ◆8.6 Properties of the Discrete Fourier Transform ◆8.7 Linear Convolution using the Discrete Fourier Transform ◆8.8 the discrete cosine transform (DCT)

从讨论周期函数的 Fourier级数的展开式出发,进而讨论 非周期函数的 Fourier积分公式及其收敛定理,并在此基础上引出 Fourier变换的定义、性质、-些计算公式及某些应用 本章的重点是求函数的ouer变换及 Fourier变换的某些应 用.函数的 Fourier变换也是本章的一个难点,要解决好这个难点, 必须掌握好 Fourier变换的基本性质及一些常用函数(如单位脉冲 函数,单位阶跃函数,正、余弦函数等)的 Fourier变换及其逆变换 的求法从而才能较好地运用 fourier变换进行频谱分析,解某些 微分、积分方程和偏微分方程的定解问题

1.1 Fourier 级数 1.2 Fourier级数复展开式 1.3 Fourier 积分公式 2.1 Fourier变换的定义 2.2 例题

§1.1 Introduction §1.2 Continue-time Signal §1.3 signal representation based on δ(t) §1.4 Linear time-invariant system §1.5 System unit impulse response §1.6 Fourier series of periodic signals §1.7 Fourier analyses of non-periodic signals—Fourier Transform §1.8 Fourier Transform of typical signals §1.9 Fourier Transform of typical signals §1.10 Properties of Fourier Transform §1.11 Fourier analyses of linear system

◆8.0 Introduction ◆8.1 Representation of Periodic Sequence: the Discrete Fourier Series (DFS) ◆8.2 Properties of the DFS ◆8.3 The Fourier Transform of Periodic Signal ◆8.4 Sampling the Fourier Transform ◆8.5 Fourier Representation of Finite-Duration Sequence: the Discrete Fourier Transform(DFT) ◆8.6 Properties of the DFT ◆8.7 Linear Convolution using the DFT ◆8.8 the discrete cosine transform (DCT)

◆8.0 Introduction ◆8.1 Representation of Periodic Sequence: the Discrete Fourier Series (DFS) ◆8.2 Properties of the DFS ◆8.3 The Fourier Transform of Periodic Signal ◆8.4 Sampling the Fourier Transform(DTFT) ◆8.5 Fourier Representation of Finite-Duration Sequence: the Discrete Fourier Transform(DFT) ◆8.6 Properties of the DFT ◆8.7 Linear Convolution using the DFT ◆8.8 the discrete cosine transform (DCT)

Fourier 变换及其逆变换 前面关于 Fourier 级数的论述都是对周期函数而言的，那么对于 非周期函数，又该如何处理呢？ 在 +∞−∞ ),( 上可积的非周期函数 f x( )可以看成是周期函数的极限 情况，处理思路是这样的： （1） 先取 f x( )在[ ,] −T T 上的部分（即把它视为仅定义在[ ,] −T T 上 的函数），再以2T 为周期，将它延拓为 +∞−∞ ),( 上的周期函数 f x T ( )；