3.1周期序列的离散傅立叶级数 3.1.1周期序列的傅立叶级数（DFS） 对于周期为N的周期序列 可用 基序列 { } 来展开

Z-Transform The DTFT provides a frequency-domain representation of discrete-time signals and LTI discrete-time systems Because of the convergence condition, in many cases. the DTFT of a sequence may not exist As a result, it is not possible to make use of such frequency-domain characterization in these cases

Later in the course we shall review various methods of designing frequency-selective filters satisfying prescribed specifications · We now describe several loworder- FIR and IIR digital filters with reasonable selective frequency responses that often are satisfactory in a number of applications Copyright 2001, S. K. Mitra

An LtI discrete-time- system is completely characterized in the time-domain by its impulse response {h[n]} We consider now the use of the DTFT and the z-transform in developing the transform- domain representations of an Lti system Copyright 2001, S. K. Mitra

Comb Filters The simple filters discussed so far are characterized either by single passband and/or a single stopband There are applications where filters with multiple passbands and stopbands are required The comb filter is an example of such filters Copyright 2001, S. K. Mitra

Stability Condition of a Discrete-Time LTI System · BIBO Stability Condition-A- discrete--time LTI system is BIBO stable if the output sequence {y[n]} remains bounded for any bounded input sequence{x[n]} A discrete-time LTI system is BIBO stable if and only if its impulse response sequence {h[n]} is absolutely summable

Discrete-Time Signals: Time-Domain Representation Signals are represented as sequences of numbers, called samples Sample value of a typical signal or sequence denoted as x[n] with n being an integer in the range-∞≤n≤∞ ·x[n] defined only for integer values of and undefined for non-integer values

脉冲响应不变法的主要缺点是频谱交叠产生的混淆,这是从S平面到Z平面的标准变换z=e的多值对应关系导致的为了克服这一缺点,设想变换分为两步: 第一步:将整个S平面压缩到S1平面的一条横带里; 第二步:通过标准变换关系将此横带变换到整个Z平面上去

电子科技大学：《计算电磁学 Computational Electronmagentics》课程教学资源（课件讲稿，有限差分法）第6章 时域有限差分法 III 6.1 激励源技术 6.2 集总参数电路元件的模拟 6.3 数字信号处理技术 6.4 应用举例（I）

MATLAB 是一个功能十分强大的系统，是集数值计算、图形管理、程序开发为一体的 环境。作为强大的科学计算平台，它几乎能满足所有的计算需求。在美国及其他发达国家的 理工科院校里，MATLAB 已成为了一门必修的课程，在科研院所、大型公司或企业的工程 计算部门，MATLAB 也是最为普遍的计算工具之一。 MATLAB 具有如下的优势和特点：