15
Discrete-Time
Modulation
The modulation property is basically the same for continuous-time and dis-
crete-time signals. The principal difference is that since for discrete-time sig-
nals the Fourier transform is a periodic function of frequency, the convolution
of the spectra resulting from multiplication of the sequences is a periodic con-
volution rather than a linear convolution.
While the mathematics is very similar, the applications are somewhat dif-
ferent. In continuous time, modulation plays a major role in communications
systems for transmission of signals over various types of channels. That appli-
cation usually is inherently a continuous-time application. However, in many
modern communication systems, signals may go through various stages and
types of modulation as they move from one channel to another, and often this
Ch1. Signals and Systems
1SIGNALS and SYSTEMS信号与系统任课老师：罗伟E-mail: teacherluowei@Ch1. Signals and Systems2•本“信号与系统”课程所讨论的主要内容是：描述确定信号与线性时不变系统的基本数学方法和分析确定信号通过线性时不变系统的基本数学方法。信号与系统四川大学电气信息工程学院201X年春（64学时）序言•要求本课程注册学生应具备：1.进行复数运算和多项式运算的能力。2.微积分学和求解常系数常微分方程的基础知识。3.电路、电子电路、电工测量技术的基本理论与实践。Ch1. Signals and Systems
31SIGNALS AND SYSTEMS信号与系统Ch1. Signals and Systems
4Main content ：1.Continuous-Time and Discrete-Time Signals（连续时间与离散时间信号）2.Transformations ofthe IndependentVariable（自变量的变换）3.Exponential and Sinusoidal Signals（指数信号与正弦信号）4.TheUnit Impulse and Unit Step Functions（单位冲激与单位阶跃函数）5.Continuous-Time and Discrete-Time Systems (连续时间与离散时间系统)6.Basic System Properties(基本系统性质)Ch1. Signals and Systems51.1 CONTINUOUS-TIME AND DISCRETE-TIME SIGNALS (p1)•Signals: physical phenomena or physical quantities, which change with time or space.•Functions of one or more independent variables.example: x(t)1.1.1 Examples and Mathematical Representation (p1) (举例与数学表示)Figure 1.1 (p2)A simple RC circuit.Ch1. Signals and Systems6A speech signalFigure 1.3 (p2) “Should we chase” 这句话的声压随时间变化的波形.Ch1. Signals and Systems
SCIENCE & TECHNOLOGY INFORMATION科技资讯信息与智能 2023 NO.18 SCIENCE & TECHNOLOGY INFORMATION科技资讯“信号与系统”中系统稳定性分析巩亚楠 魏德旺 刘俊良 李淑晴 吕海燕*(临沂大学 山东临沂 276000)摘要： “信号与系统”是电子信息类本科阶段的专业基础课。在学习的过程中，很多同学只是记住知识点，不明白它们之间的逻辑关系，不会灵活运用。该文旨在利用思维导图的方式对系统稳定性分析方法进行总结，描述了连续时间系统和离散时间系统的稳定性，对每个系统提出了两种分析方法，即时域分析法和变换域分析法，对两种方法的具体分析过程做出了详细的说明，并对系统稳定性给出了4种判别方法。借助思维导图，帮助学生更好地理解知识，充分调动学生学习的积极性。关键词： 信号与系统 思维导图 系统稳定性分析 连续时间系统 离散时间系统中图分类号： G64文献标识码： A 文章编号： 1672-3791(2023)18-0078-04Analysis of the System Stability in "Signals and Systems"GONG Yanan WEI Dewang LIU Junliang LI Shuqing LYU Haiyan*(Linyi University, Linyi, Shandong Province, 276000 China)Abstract: "Signals and systems" is a professional basic course of the undergraduate level of electronic information. In the process of learning, many students just remember knowledge points, but they don't understand the logic rela‐tionship among them and cannot use them freely. This paper aims to summarize the analytical method of the system stability by mind mapping, describes the stability of the continuous-time system and the discrete-time system, puts forward two analytical methods for each system, namely the time-domain analysis method and the transform-domain analysis method, explains in detail the specific analytical process of the two methods, and also presents four discriminant methods for the system stability. With the help of mind mapping, students can better comprehend knowledge and fully mobilize their enthusiasm for learning.Key Words: Signals and Systems; Mind mapping; System stability analysis; Continuous-time system; Discrete-time system1 “信号与系统”课程地位“信号与系统”作为信息、电子、自控、通信等专业的专业基础课，是为后续数字信号处理、数字图像处理、通信原理、自动控制等课程的学习打下基础，“信号与系统分析”被认为是一门理解困难、计算繁杂、偏理论模型的课程。课程知识本身的复杂性、抽象性等特点，使学生在学习过程遇到很多的困难，主要表现在以下两个方面：（1）课程体系庞大、分支众多、知识抽象，在学习过程中往往难以找到各个知识相互间的联系，难以把握重点，使对基础知识理解不透彻导致核心知识理解困难；（2）课程主要在“时间域”及“频率域”下研究时间函数
1 Digital Signal Processing Using Computer-Based Methods -
Course Design for the 4th Edition
Introduction
Digital Signal Processing (DSP) is an area of study that
has witnessed significant growth and advancement in recent
times. Technological advancements have made it possible to
work with signals and signals processing methods more
effectively and efficiently. The use of computers has also
contributed significantly to the development of DSP methods.
In this course design, we will provide an overview of the
Digital Signal Processing course designed for the 4th edition
of the book titled Digital Signal Processing Using Computer-Based Methods.
Overview of the Course
This course is designed to provide students with a
fundamental understanding of digital signal processing
concepts, their applications, and techniques for analyzing
