上海交通大学：《信号与系统 Signals and Systems（B类）》教学资源_EI210 LECTURE NOTES Chapter 1（Part I）Signals and Systems

EI210 LECTURE NOTES Dianguang Ma Spring 2010

EI210 LECTURE NOTES Dianguang Ma Spring 2010

Course Information ·Code:El210 ·Credits:3 Prerequisite:Calculus,Basic Circuit Theory Required Textbook:Signals and Systems,2/e, by Alan V.Oppenheim and Alan S.Willsky, Publishing House of Electronics Industry, 7505378456,2002. Lecturer:MA Dianguang,dgma@sjtu.edu.cn ·TA:XIANG Zheng

Course Information • Code: EI210 • Credits: 3 • Prerequisite: Calculus, Basic Circuit Theory • Required Textbook: Signals and Systems, 2/e, by Alan V. Oppenheim and Alan S. Willsky, Publishing House of Electronics Industry, 7505378456, 2002. • Lecturer: MA Dianguang, dgma@sjtu.edu.cn • TA: XIANG Zheng

Course Information ·Topics Signals and Systems (Chapter 1) Linear Time-Invariant Systems(Chapter 2) Fourier Series Representations of Periodic Signals(Chapter 3) - The Continuous-Time Fourier Transform(Chapter 4) The Discrete-Time Fourier Transform (Chapter 5) - Time and Frequency Characterization of Signals and Systems (Chapter 6) Sampling (Chapter 7) Communication Systems(Chapter 8) The Laplace Transform (Chapter 9) The z-Transform(Chapter 10)

Course Information • Topics – Signals and Systems (Chapter 1) – Linear Time-Invariant Systems (Chapter 2) – Fourier Series Representations of Periodic Signals (Chapter 3) – The Continuous-Time Fourier Transform (Chapter 4) – The Discrete-Time Fourier Transform (Chapter 5) – Time and Frequency Characterization of Signals and Systems (Chapter 6) – Sampling (Chapter 7) – Communication Systems (Chapter 8) – The Laplace Transform (Chapter 9) – The z-Transform (Chapter 10)

Course Information 。Grading Ten Problem Sets:? -Three Matlab Labs:? Two Exams ·Midterm Exam:?% 。Fianl Exam:?%

Course Information • Grading – Ten Problem Sets: ?% – Three Matlab Labs: ?% – Two Exams • Midterm Exam : ?% • Fianl Exam: ?%

Chapter 1(Part I) Signals and Systems

Chapter 1 (Part I) Signals and Systems

Introduction In this chapter,we begin our development of the analytical framework for signals and systems by introducing their mathematical description and representations

Introduction • In this chapter, we begin our development of the analytical framework for signals and systems by introducing their mathematical description and representations

What Is a Signal？ A signal is formally defined as a function of one or more variables that conveys information on the nature of a physical phenomenon. When the function depends on a single variable, the signal is said to be one dimensional. When the function depends on two or more variables,the signal is said to be multidimensional

What Is a Signal? • A signal is formally defined as a function of one or more variables that conveys information on the nature of a physical phenomenon. • When the function depends on a single variable, the signal is said to be one dimensional. • When the function depends on two or more variables, the signal is said to be multidimensional

A Signal Is a Function of Time We focus our attention on signals involving a single independent variable.For convenience,we will generally refer to the independent variable as time,although it may not in fact represent time in specific applications

A Signal Is a Function of Time • We focus our attention on signals involving a single independent variable. For convenience, we will generally refer to the independent variable as time, although it may not in fact represent time in specific applications

Classification of Signals Five methods of classifying signals,based on different features,are common: -Continuous-time and discrete-time signals -Even and odd signals -Periodic and nonperiodic/aperiodic signals Deterministic and random signals Energy and power signals

Classification of Signals • Five methods of classifying signals, based on different features, are common: – Continuous-time and discrete-time signals – Even and odd signals – Periodic and nonperiodic/aperiodic signals – Deterministic and random signals – Energy and power signals

Continuous-Time and Discrete-Time Signals A signal is said to be a continuous-time signal if it is defined for all time. Continuous-time signals are defined for a continuum of values of the independent variable. A discrete-time signal is defined only at discrete instants of time.Thus,the independent variable has discrete values only,which are usually uniformly spaced

Continuous-Time and Discrete-Time Signals • A signal is said to be a continuous-time signal if it is defined for all time. • Continuous-time signals are defined for a continuum of values of the independent variable. • A discrete-time signal is defined only at discrete instants of time. Thus, the independent variable has discrete values only, which are usually uniformly spaced