回顾 1、可视化程序设计 2、一字符界面的缺点和图形用户界面的需求 3、可视化程序设计的基本思想 4、使用VB开 Windows发应用程序的优点 5、介绍Visual Basic集成开发环境 6、使用 Visual Basic提供的各种编程控件 7、在 Visual Basic中编译和执行程序

回顾 1、基本数据口型 2、口量和常量 3、口量和常量的作用域 4、操作符和表达式 5、流程控制语句

回顾 1、使用图片框控件和图像控件 2、使用框架中的复选框和选项按钮 3、使用列表框和组合框控件 4、使用 Timer控件创建 Timer应用程序

回顾 1、设计菜单和编写菜单代码 2、设计和使用窗口中的弹出菜单 3、使用系统对话框输入数据 4、使用对话框控件 5、设计和使用自定义对话框

3.1 Discrete-Time Fourier Transform Definition- The discrete-time Fourier transform (DTFT) X(eio) of a sequence x[n] is given by jae In general,() is a complex function of the real variable and can be written as X(eio) Xre(eio) +j Xim(eio)

6.1 Introduction The convolution sum description of an LTI discrete-time system can, in principle, be used to implement the system For an IR finite-dimensional system this approach is not practical as here the impulse response is of infinite length · However, direct implementation of the IIR finite-dimensional system is practica

Introduction Ideally, the system parameters along with the signal variables have infinite precision taking any value between -oo and · In practice, they can take only discrete values within a specified range since the registers of the digital machine where they are stored are of finite length

1.1 Introduction Any problems about signal analyses and processing may be thought of letting signals trough systems. f(t) y(t) h(t) From f(t) and h(t), find y(t), Signal processing From f(t) and y(t), find h(t), System design From(t)andh(t), find(t), Signal reconstruction

4.1 LTI Discrete-Time Systems in the Transform Domain · Such transformdomain- representations provide additional insight into the behavior of such systems It is easier to design and implement these systems in the transform-domain for certain applications We consider now the use of the DtFt and the z-transform in developing the transform- domain representations of an LTI system

第一讲函数概念 课后作业: 阅读:第一章1.1--..1—25, 自学: 练习 作业pp3-4习题1.1:2;7 pp7-8习题1.2:1.(3),(4)3.(3),(4);4;7;8 pp12习题1.3:59;11 pp19-20习题1.4:1. pp25-26习题1.5:1.(2),(11)2.(6);3.(2)5.(1)