Transcript 20130624-EE235-Lecture1x

Signals and Systems
EE235
Leo Lam
Leo Lam © 2010-2013
Today’s menu
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Introductions
Class logistics and expectations
Help available
Course material starts!
Leo Lam © 2010-2013
Introduction
• Who is this bozo?
– Email: [email protected]
– Anonymous message welcome
– Office: CSE 234
• Performance guarantee
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You are my customers
12-hour email response
Reasonable and humane
Candy Bar Challenge
• Five questions!
Leo Lam © 2010-2013
Introduction
• TA: Peifeng Jing
– Email: peifen11@uw
– Office hours: TBD
– MATLAB wiz @ Lab
Leo Lam © 2010-2013
Introduction
• You!
Leo Lam © 2010-2013
Goal
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Introduction to the “language” of “signals”
Manipulating the language (the “system”)
Using MATLAB to play with it
Preparation for DSP etc.
System level thinking
Engineering “sense”
Communicating with each other technically
Discipline in practicing engineering
Leo Lam © 2010-2013
Logistics
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Four lectures
One lab per week
Lab begins this week (need EE account)
Grading
– 60% consistent work (homework/lab)
– 40% “exams” (1 week-5 midterm/1 Final)
– Fair, consistent, not “mean”
• Website:
wp.ee.washington.edu/ee235sum2013/
• Pre-req: Math 136,307,Amath 351, PHY 122
or CSE 142 etc.
Leo Lam © 2010-2013
Expectations
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Active, curious, question
Show up and know where to find info
Work together, and practice a lot
Integrity, honor and discipline
• Lab (six labs)
– Read the manual
– Communicate clearly
– Collaborate
Leo Lam © 2010-2013
Textbook
• Not required, but highly recommended
• Three more books recommended:
– Matlab Primer (for Lab)
– Schaum’s Outline of Signals and Systems
– Advanced Engineering Mathematics
Leo Lam © 2010-2013
Help?
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Facebook group – Your learning social media
Me and TA (office hours)
Each other (and meet new friends!)
HKN help for 215, 233, 235 (may not be
available in the summer)
Leo Lam © 2010-2013
Questions?
• Before the launch…
Leo Lam © 2010-2013
Examples of a “signal”?
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Electrical parameter over time
Radio over time and space
Sound/Pressure over time
Medical parameters over time
Images
Video
Stock prices (discrete time)
People in a room daily (discrete variable/time)
Leo Lam © 2010-2013
Definition: Signal
• A signal is a set of information or data that
can be modeled as a function of one or more
independent variables.
Leo Lam © 2010-2013
There’s a theme here
Continuous time
Continuous variable
Continuous time
Discrete Variable
e.g. talking to you
e.g. people in the room
Discrete time
Continuous variable
Discrete time
Discrete variable
e.g. daily temperature
e.g. data recorded on CD
Leo Lam © 2010-2013
Taking a signal apart
Offset (atmospheric pressure)
A sound signal
Frequency
Amplitude
s(t )  A sin(2 f0t )  a0
A+a0
a0
T
Leo Lam © 2010-2013
t (seconds)
Frequency
f 0  196Hz
g (t )  sin(2f 0t )
=
t
time-domain
Leo Lam © 2010-2013
(seconds)
196
f
(Hz)
frequency-domain
t to f
196
293.66
293.66
659.26
t (seconds)
Leo Lam © 2010-2013
F (Hz)
Combining signals
Leo Lam © 2010-2013
Summary: Signals
• Signals carry information
• Signals represented by functions over time or
space
• Signals can be represented in frequency
domain
• Signals can be summed in both time and
frequency
Leo Lam © 2010-2013