CEN340 Signals and Systems By Dr. aBDULWADOOD ABDULWAHEED LECTURE SLIDES COURTESY OF DR. ANWAR M. MIRZA Office No. 2210 aabdulwaheed@ksu.edu.sa http://fac.ksu.edu.sa/aabdulwaheed/ الدكتور / عبدالودود عبدالوحيد Lecture No. 1 Department of Computer Engineering, College of Computer and Information Sciences, King Saud University, Riyadh, Kingdom of Saudi Arabia 11/28/2018

Class Particulars Credit Hours: 3 + 1 Course Structure: Three Lectures a week (2 hours). Tutorial session of 2 hours Class Timings: Sat, Mon, Wed 8:00-9:50 Mon 13:00-14:40 Tutorial/Q&A 11/28/2018

Pre-requisites The course requires as pre-requisites: Math 204 and EE201 Differential Equations 11/28/2018

Major Topics Covered and Schedule in Weeks Weeks (Approx.) Introduction to mathematical software tool ½ Signal classification and basic operations on signals 1 Time-domain analysis of signals and systems Fourier representations of signals and systems 3/2 Applications of Fourier representations Laplace transform and its applications Modulation /demodulation of am/fm signals Review and evaluation 1/2 11/28/2018

Approximate Time in Hours Course Outline Topic Approximate Time in Hours 1 Introduction to Mathematical Software Tool 3 2 Introduction to Signals and Systems (1.1 – 1.5) Basic System Properties (1.6) 4 LTI Systems: The Convolution Sum (2.1) 5 LTI Systems: The Convolution Integral (2.2) 6 Properties of LTI Systems (2.3) 7 LTI Systems described by differential equations and difference equations (2.4) Mid Term Exam 1 8 Fourier Series Representation (3.0 – 3.5) 9 Continuous-Time Fourier Transform and Applications (Chapter 4) 10 The Laplace Transform and Its Applications (Chapter 9) Mid Term Exam 2 Modulation and Demodulation AM/FM (Chapter 8) 11 Application to Communication Systems (Chapter 8) 12 Review 11/28/2018

Recommended Texts Primary: Supplementary: Openheim A., Willsky A. and S. Nawab, Signals and Systems, 2nd Ed., 1997, Prentice Hall. Lathi B. P., Modern Digital and Analog Communication Systems, 3rd Ed., 1998, Oxford University Press. Supplementary: Kamen, E. W. and Heck, B. S., Fundamentals of Signals and Systems using the Web and Matlab, 3rd Ed., 2007, Prentice Hall Haykin, S, Communication Systems, 4th Ed., 2001, John Wiley and Sons, New York 11/28/2018

Evaluation and Grading Activity Marks Quizzes 05 Assignments 15 Mid-term Test 1 20 Mid-Term Test 2 Final Exam 40 Total 100 11/28/2018

Quizzes and Assignments Policies Frequent quizzes will be taken. Students are required to attend the classes regularly and come prepared in each class. Assignments No assignments will be accepted after due date. Programming assignments should be well documented. There are “no groups” for assignments. Each student is expected to do and submit the assignment individually. Students are “not” allowed to “copy” each other’s work. 11/28/2018

What is a Signal? A signal is an abstraction of any measurable quantity that is a function of one or more independent variables such as time or space. Examples Voltages and currents are electrical signals Sound is a mechanical signal This very slide is a two dimensional light signal forming in the retina of your eye 11/28/2018

Broad Classes of Signals Continuous-Time (CT) Signals Discrete-Time (DT) Signals A continuous-time (CT) signal is one that is present at all instants in time or space, such as oscillating voltage signal. A discrete-time (DT) signal is only present at discrete points in time or space. For example closing stock market average is a signal that changes only at discrete points in time (at the close of each day). 11/28/2018

What is a System? A system is an abstraction of anything that takes an input signal, operates on it, and produces an output signal. A system generally establishes a relationship between its input and its output. Examples could be car, camera etc. Systems that operate on continuous-time signal are known as continuous-time (CT) systems. Systems that operate on discrete-time signals are known as discrete-time (DT) systems. 11/28/2018

Continuous-Time and Discrete-Time Signals Examples and Mathematical Representation A simple RC circuit with source voltage V and capacitor voltage Vc, both of which are signals in time An automobile responding to an applied force f from the engine and to a retarding frictional force proportional to the automobile’s velocity v. Both f and v are functions (signals) of time 11/28/2018

Continuous-Time and Discrete-Time Signals Examples and Mathematical Representation Signals are represented mathematically as functions of one or more ‘independent variables’. A speech signal can be represented mathematically by acoustic pressure as a function of time. A picture can be represented by brightness (intensity of light) as function of two spatial variables. 11/28/2018

Continuous-Time and Discrete-Time Signals Examples and Mathematical Representation Notation To distinguish between continuous-time and discrete-time signals, we will use The symbol ‘t’ to denote the continuous-time independent variable and ‘n’ to denote the discrete-time independent variable. We will enclose the independent variable in parentheses ‘( . )’ and for discrete-time signals, we will use brackets ‘[ . ]’ x(t) x[n] t -1 0 1 2 3 4 n 11/28/2018

Continuous-Time and Discrete-Time Signals Examples and Mathematical Representation Important Points to Note: The discrete-time signal x[n] is defined only for integer values (sometimes both positive and negative) of the independent variable. This is why sometimes x[n] is also called “Discrete-Time Sequence”. A very important class of discrete-time signals arises from the sampling of continuous-time signals. This is very important for their implementation on digital computers (which can work only with discrete-time signals). 11/28/2018

Software Tool: Matlab® Matlab ® is a software tool for computation in science and engineering. Developed, published and trademarked by The MathWorks, Inc. Originally developed as a “Matrix Laboratory” but now used in applications in almost all areas of science and engineering. It has a rich collection of tool boxes covering basic mathematics, graphics, differential equations, electric/electronic circuits, partial differential equations, simulation problems, control systems, signal processing, image processing, statistics, symbolic computations etc, http://www.mathworks.com/help/pdf_doc/matlab/getstart.pdf http://www.mathworks.com/academia/student_center/tutorials/launchpad.html 11/28/2018

Getting Started Guide Starting and Quitting the MATLAB Program . . . . . . . . . 1-7 Matrices and Magic Squares . . . .. . . . . . . . . . . . . . . . . . 2-2 Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11 Working with Matrices . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17 More About Matrices and Arrays . . . . . . . .. . . . . . . . . . 2-21 Plotting Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2 Plotting Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3 Graph Components . . . . . . . . . .. . . . . . . . . . . . . . . . . . . 3-7 Choosing a Graph Type . . . . . . . . . . . . . . . . . . . . . . . . . 3-17 Editing Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25 11/28/2018

Getting Started Guide Interactive Plotting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-31 Preparing Graphs for Presentation . . . . . . . . . . . . . . . . 3-45 Basic Plotting Functions . . . . . . . . . . . . . . . . . . . . . . . . . 3-58 Creating Mesh and Surface Plots . . . . . . . . . . . . . . . . . . 3-73 Plotting Image Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-81 Printing Graphics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-83 Understanding Handle Graphics Objects . . . . . . . . . . . 3-86 Flow Control . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . 4-2 Other Data Structures . . . . . . . . . . . . . . . . . . . . . .. . . . . . 4-9 Scripts and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20 11/28/2018

Getting Started Guide What Is GUIDE? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2 Laying Out a GUI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3 Programming a GUI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7 Desktop Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2 Command Window and Command History . . . . . . . . . 7-5 Getting Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7 Workspace Browser and Variable Editor . . . . . . . . . . . . . 7-13 11/28/2018

Assignment Practice the Matlab ® commands from the sections listed in the previous slides. Read the topics covered from the text book. 11/28/2018