Signals and Systems 1
Lecture 1
Dr. Ali. A. Jalali
August 19, 2002
Signals and Systems 1
Proposed Main Textbook
 Contemporary Linear Systems,
Using MATLAB
 By Robert D. Strum and Donald
E. Kirk, Book Ware Companion
Series, ISBN 0-534-37172-8, year
2000.
EE 327 fall 2002
Signals and Systems 1
1. Homework Policy
2. Homework will be posted on
the class web page or will be
given on the class by
instructor each time, and is
due at midnight on the due
date (usually Monday).
EE 327 fall 2002
Signals and Systems 1
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2.
Project
Towards the end of the semester, each study
group will complete a project applying the
concepts they have learned in the class. The
groups will present their projects (use power
points and Microsoft Words) in class or your
Web Pages. See class web pages for more
information.
EE 327 fall 2002
Signals and Systems 1
1. MATLAB and MATLAB Workshop
2. MATLAB will be required for some
homework problem and projects. You
have the option of either purchasing the
student edition from the bookstore, or
using the workstation or PC
laboratories (e. g. ESB 813).
EE 327 fall 2002
MATLAB
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Matlab is required for this course. The following toolboxes are also
required: Symbolic Math, Signal Processing, and Control Systems.
There several options for obtaining Matlab.
The student version of Matlab is recommended and endorsed for this
course. It comes with the Symbolic Math toolbox. The Signal
Processing and Control Systems toolboxes can also be purchased at a
reduced price with student ID. The student version of Matlab does not
expire.
Alternatively, a one year license for the professional version of Matlab
with the required toolboxes and many others can be purchased through
the ECE office for about $100.
The professional version with toolboxes is also available on all ECS
computers.
EE 327 fall 2002
Signals and Systems 1
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Basis of Final Grade
Test # 1:
15 %
Test # 2:
15 %
Test # 3:
15 %
Final Exam:
30 %
Group Project:
10 %
Homework:
10 %
Attendance, Random
Quizzes and Website links lists:
5%
NOTE: The Exams are closed book.
EE 327 fall 2002
Signals and Systems 1
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Course Web Page
A homepage is maintained for this class at:
www.csee.wvu.edu/~jalali/ee327.html
This homepage will contain important
announcements and materials handed out in
class, including lecture notes, homework
assignments, MATLAB files, and
homework/exams solutions.
In addition, it might be a MIX page for the
course that you can access at:
http://www.mix.wvu.edu
EE 327 fall 2002
EE 327 fall 2002
http://www.csee.wvu/~jalali
Signals and Systems 1
Lecture # 1
Introduction to Signals
EE 327 fall 2002
Signals and Systems 1
Reasons for studying linear
systems theory
2. Mathematical description
3. MATLAB generation of signals
and sequences
4. A road map of domains, models
and operations
1.
EE 327 fall 2002
Reasons for studying linear systems theory
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Engineers, scientists, and mathematicians all use
linear systems theory because it is the
foundation for building many of the things we
use in our daily lives.
The theory of Linear systems provides
powerful tools for analysis and design, and
many communications, control, and signal
processing systems can be approximated by
linear models.
EE 327 fall 2002
Reasons for studying linear systems theory
1.
2.
3.
By applying these tools to suitable mathematical
models, we can design and develop better
systems and also shorten the production cycle.
Computer simulation plays a central role in
applying linear systems theory and there are
now available powerful and easy-to-use software
packages.
One of these, MATLAB, is used extensively in
this class.
EE 327 fall 2002
Reasons for studying linear systems theory
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We will consider both discrete-time and
continuous-time systems in this class.
Discrete-time systems is referred to a systems
whose signals change only in discrete-time
instants.
The systems whose signals vary continuously
with time called continuous time systems.
Usually they refer to discrete and continuous
systems.
EE 327 fall 2002
Signals and Systems
(Signals & Systems)
Signals
Electrocardiogram (ECG or EKG)
EE 327 fall 2002
Sequences
Systems
Sound is an example of signal
1. What is sound?
2. How can we characterize our
perceptions of sound?
3. How can we classify sounds?
4. How can we measure sounds?
EE 327 fall 2002
Sound
1. Pressure variations
2. Microphone converts to voltage
3. Oscilloscope displays voltage
change with time (a waveform)
EE 327 fall 2002
Signals and Systems
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A signal is the physical form of a waveform, like a
sound wave or a radio wave.
Time is often the independent variable for signal.
The independent variable can be 1-D or 2-D (space x, y
in image), 3-D or N-D
A system is an object or channel that changes a signal
that passes through it.
Amplifiers are systems that increase the amplitude of
signals passing through them.
Attenuators are systems that decrease the amplitude of
signals passing through them.
EE 327 fall 2002
Signals and Systems
1. This course deals with mathematical
methods used to describe signals and
to analyze and synthesize systems.
2. Signals are variables that carry
information
3. Systems process input signals to
produce output signals
EE 327 fall 2002
Signals and Systems
1.
Signals
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physical form of a waveform
e.g. a sound, electrical current, radio wave
Systems
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2.
a channel that changes a signal that passes through it
e.g. a telephone connection, a room, a vocal tract
Input Signal
EE 327 fall 2002
System
Output Signal
Signals and Systems
1. Description of signals
1. waveform, amplitude, period, fundamental
frequency
2. spectrum, harmonic, harmonic amplitude
& phase
2. Description of systems?
1. how to characterize them?
2. how to measure them?
EE 327 fall 2002
Signals:
1. Classification of Signals
1. Deterministic and Stochastic signals
2. Periodic and Aperiodic signals
3. Continuous time (CT) and Discrete time (DT)
4. Causal and anti-causal signals
5. Right and left sided signals
6. Bounded and unbounded signals
7. Even and odd signals
EE 327 fall 2002