1. CEN340 Signals and SystemsBy
Dr. aBDULWADOOD ABDULWAHEED
LECTURE SLIDES COURTESY OF DR. ANWAR M. MIRZA
Office No. 2210
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

2. 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
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3. Pre-requisites The course requires as pre-requisites:
Math 204 and EE201
Differential Equations
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4. Major Topics Covered and Schedule in Weeks
Weeks (Approx.)
Introduction to mathematical software tool
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
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5. 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
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6. 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
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7. Evaluation and Grading
Activity
Marks
Quizzes 05
Assignments 15
Mid-term Test 1 20
Mid-Term Test 2
Final Exam 40
Total
100
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8. 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.
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9. 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
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10. 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).
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11. 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.
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12. 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
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13. 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.
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14. 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 n
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15. 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).
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16. 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,
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17. Getting Started Guide
Starting and Quitting the MATLAB Program
Matrices and Magic Squares
Expressions
Working with Matrices
More About Matrices and Arrays
Plotting Data
Plotting Techniques
Graph Components
Choosing a Graph Type
Editing Plots
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18. Getting Started Guide
Interactive Plotting
Preparing Graphs for Presentation
Basic Plotting Functions
Creating Mesh and Surface Plots
Plotting Image Data
Printing Graphics
Understanding Handle Graphics Objects
Flow Control
Other Data Structures
Scripts and Functions
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19. Getting Started Guide
What Is GUIDE?
Laying Out a GUI
Programming a GUI
Desktop Overview
Command Window and Command History
Getting Help
Workspace Browser and Variable Editor
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20. Assignment
Practice the Matlab ® commands from the sections listed in the previous slides.
Read the topics covered from the text book.
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