Current issues

Double lecture (2x2=4hrs) is on 29.01.2008. We will use this time for Exam0 and a lecture.

The Exam 0 is open to all EDISP students. It does not interfere with your right to have 2 exams in the session time. This way you have 3 exam dates possible.

Exam 1 is on Feb 04, 11 - 14, room 204 (according to the official assignment)

Exam 2 will be conducted as ORAL. Possible dates are Thu (Feb 7) and Fri (Feb 8) - NOT as shown in the official tables.
Please contact me if you need to take Exam 2.

There will be a possibility to repeat Test1 and Test2 (one or both) - just after the exam 0, by doing extra problems in extra time.
Students unable to come on 29.01 will be given the option to repeat tests on Feb 04 (after the Exam1)

In all cases (Exam 0/1/2 and test/test_repeat)the best score counts.

Rules: (same as with T1/T2): Allowed are YOUR OWN notes (handwritten on paper or on printed lecture slides). No books, no photocopies of other person notes.

Final score

The rule:
if [(score>34.5)]; then score *= 2; fi
takes scores from the regular work during the term. In other words, test correction does NOT count here.
The possibility to repeat (correct) T1 and T2 will be given during Exam 0 and Exam 1.

Examples of final tests (historical)

One test. Another test.

There is no guarantee that the current test be identical ;-). It will be similar (the lecture was similar), but I might also put more focus on different subjects. The only base is the lecture content (live one, not only the published slides ....).

The main rule: exam covers the whole course content (sampled), including the T1(H1)+T2(H2) area and also the lectures after the H2.

Shortcuts

Home page of EDISP
(English) DIgital Signal Processing course
winter 2007/8

Schedule

Short info: labs will be on Mondays, 8-12 or 12-16.
For the introductory lab (lab0) we met on 8 Oct, 9:15 room 022.
Next lab (lab1) will be 29.10.2007 for P (8:15-12) subgroup, 05.11.2007 for N (8:15-12) subgroup

Books

A. V. Oppenheim, R. W. Schafer, Discrete-Time Signal Processing, Prentice-Hall 1989 (or II ed, 1999; also acceptable previous editions entitled Digital Signal Processing).

A free textbook covering some of the subjects can be found here: http://www.dspguide.com/pdfbook.htm
The book is slightly superficial, but it can be valuable - at least as a quick reference. Additional books available in Poland:

• R.G. Lyons, Wprowadzenie do cyfrowego przetwarzania sygnałów (WKiŁ 1999)
• Craig Marven, Gilian Ewers, Zarys cyfrowego przetwarzania sygnałów, WKiŁ 1999 (simple, slightly too easy) [en: A simple approach to digital signal processing, Wiley & Sons, 1996]
• Tomasz P. Zieliński, Od teorii do cyfrowego przetwarzania sygnałów, WKiŁ 2002 (and next edition with slightly modified title)

Please remember:

• there are notation differences between lecture and "dspguide"
• The official book is Oppenheim & Schafer (though notation is sometimes different too)
• no book is obligatory in these circumstances

Probably the best choice is to buy O&S. It'll serve you for years, if you are interested in DSP. And it contains a lot of PROBLEMS to solve and learn!

Or you may prefer to buy/borrow a laboratory scriptbook, which is in Polish language (Cyfrowe Przetwarzanie Sygnałów, red. A Wojtkiewicz, Wydawnictwa PW).
 

Lecture slides

Lecture number = week number in schedule.

• Lecture 1 slides: newlect1.pdf but please don't read the schedule here - use the schedule.pdf
• Lecture 2 slides: newlect2.pdf
  Convolution example: conv_exampl.jpg
• (Lecture 3=EMISY)
• Lecture 4 slides: newlect3.pdf
• Lecture 5 slides (we'll also finish the newlect3.pdf): newlect4.pdf
  Homework was given this day!
• Lecture 6:
  Homework (hand-written on paper, worth up to 2 points) is due at the BEGINNING of the lecture.
  Review will be done (1 hour, based also on your homework errors)
  Windowing for DFT, DFT applications (1 hour lecture) slides: newlect5.pdf
• Lecture 7: Thursday, no lecture :-(
  
• Lecture 8: Instantaneous spectrum: newlect6.pdf
  and Z-transform newlect7.pdf
  
• Lecture 9: 1 hour test, 10pts worth: bring YOUR OWN notes (handwritten on paper or on printed lecture slides). No books, no photocopies of other person notes.
  1 hour lecture - Filters part I:newlect8.pdf
• Lecture 10: Filters part II:newlect9.pdf
• Lecture 11: Filters part III: newlect10.pdf
• Lecture 12: Digital signal processors: lect12_dsp.pdf(and OHP foils to be seen at the lecture)
• Lecture 13/14: Merry Christmas and Happy New Year
• Lecture 15: Random DT signals lect9.pdf
• Lecture 16: test II + 2D signal processing lect13.pdf
• Lecture 17: 2D signal processing+advanced techniques+review
• Lecture 18: (total: 4hours!!!!)Exam 0+advanced techniques

Lab info: example lab exercises

Disclaimer:

Openly speaking, they are exercise sets current at the time of posting. I reserve the right to make some important modifications before the actual lab, to give different sets to different groups etc. (and I usually DO review the text before giving it....).

• Lab 0: Introduction, Matlab
• Lab 1: Signals, systems, frequency
  • Simple MATLAB usage: make a vector, plot x - y plot with proper data on axes, make a simple m-function.
  • DT signal as a sampled CT signal: plot sample values of a sin() with a frequency of 1 kHz, sampled with 10 kHz (etc). Put x-axis values as sample index, CT instant, ....
  • Normalized frequency concept (e.g. What is the θ value in the above example?)
  Lab exercises: lab0a.pdf
• Lab 2: Spectral analysis (+ continuation of lab1)
  • Impulse response of a system; initial conditions etc.
  • DFT properties, effect of limited observation time (windowing)
  • Spectrum of a rectangular impulse
  Lab exercises: lab2plus1cd.pdf
• Lab 3: Instantaneous spectrum Lab exercises: lab03.pdf
• Lab 4: Filter design Lab exercises: lab4.pdf
• Lab 5: we don't do it (I'm just using old numbering scheme with 7 labs....)
• Lab 6: Signal processors Lab exercises: lab6.pdf
• Lab 7: Image processing Lab exercises: lab7.pdf

Past things archive (Attic)

Remarks about TEST1

You may download test1 forms here: (A) (B). Use them for studying for the final exam. Please don't learn solutions and specific methods, learn the fundamentals that lead to the solution method.

I won't give exact solutions - you'd be tempted to learn them without understanding - but here are hints for your hard work on solving the test:

• Start the work now, while your memory of the test is fresh.
• Have a good book on complex numbers artithmetics.
• Problem 1:
  • Stability: prove by saying "if x(n) is bounded by L, y(n) is bounded by 3.86*L" or by checking some property of h(n) (your job to find which property).
  • Causality: "for calculating y(n) we don't need x(n+positive integer)"
  • Linearity/TI: you need to calculate (linear combination/shift) of T(x[n]) AND T((linear combination/shift)x[n]) and show they are the same.
• Problem 2: The sampling freq. was too small. So, effective frequency of sampled signal was fn=f/fs-k*fs, with k chosen so that |fn|<0.5. And the signal period MUST be integer - there were some silly errors from bad rounding!!!
• Problem 3: Go back to the lecture on FFT. Direct computation has complexity of O(n^2), FFT is better - but it is NOT O(n) as you assumed. Please try to understand what O(xxx) means and use it on some examples.
• Problem 4: δ(n) is an one-nonzero-sample signal with limited energy. Thus you may safely use the FT definition, the infinite sums will reduce to two non-zero terms. Then it is a matter of simple calculations, especially if you want to sketch the function - check at θ=0, π/2, π an you are done. Then recall that DFT is FT sampled in spectrum.
• Problem 5: if an impulse has length L, and h(n) lenght N, then the convolution of these has max length equal to......; next, the signal is a sum of TWO such impulses, use the linearity property..... Maybe you should calculate some simple convolutions on paper (and check with Matlab/Octave: plot(conv(x,y)) )
• Problem 6: find the expression for a transform in slides; analyze it by naked eye (or plot abs() if you prefer) and count; don't guess!
• Problem 7: Recall how we made a δ(n) from u(n). A rectangular impulse can be made from two u(n) signals scaled and shifted, so use the LTI property to make y(n) from two k(n).....

Remarks about Homework 1

I must draw your attention to the fact that the popular solution for ex.5 is not correct. Please try to understand properties of DFT better, because the test exercises will make use of that.
The correct way to solve ex.5 is to:

• identify the construction of new sequence from the old one
• find some basic operations:
  • zero-padding (=adding new samples in θ domain between old samples)
  • shift (by N/2 = modulation by (-1)^n in θ domain)
  • time inversion (=conjugation in θ domain)
  • linear operations (=the same in θ)
• find out that the interesting samples of new spectrum can be constructed from the samples of the old one treated by above basic operators

Test 2 content

Rules: (same as with T1): T2 will be 1 hour test, 10pts worth. Allowed are YOUR OWN notes (handwritten on paper or on printed lecture slides). No books, no photocopies of other person notes.