Leo Lam © Signals and Systems EE235 Leo Lam

Leo Lam © Today’s menu Introductions Class logistics and expectations Help available Course material starts!

Leo Lam © Introduction Who is this bozo? – –Anonymous message welcome –Office: CSE 234 Performance guarantee –You are my customers –12-hour response –Reasonable and humane –Candy Bar Challenge Five questions!

Leo Lam © Introduction TA: Peifeng Jing – –Office hours: TBD –MATLAB Lab

Leo Lam © Introduction You!

Goal 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 ©

Logistics 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 © Expectations 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

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 ©

Help? 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 © Questions? Before the launch…

Examples of a “signal”? 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 ©

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 ©

There’s a theme here Continuous time Continuous variable e.g. talking to you Continuous time Discrete Variable e.g. people in the room Discrete time Continuous variable e.g. daily temperature Discrete time Discrete variable e.g. data recorded on CD Leo Lam ©

Taking a signal apart Leo Lam © a0a0 T t (seconds) A+a 0 A sound signal Offset (atmospheric pressure) Frequency Amplitude

Frequency Leo Lam © t (seconds)f (Hz) = time-domainfrequency-domain

t to f Leo Lam © t (seconds) F (Hz)

Combining signals Leo Lam ©

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 ©