Everything we do, everything that happens around us, obeys the laws of probability. We can no more escape them than we can escape gravity... "Probability," a philosopher (Bishop Butler) once said, "is the very guide of life." We are all gamblers who go through life making countless bets on the outcome of countless actions.

Every field of science is concerned with estimating probability. A physicist calculates the probable path of a particle. A geneticist calculates the chances that a couple will have blue-eyed children. Insurance companies, businessmen, stockbrokers, sociologists, politicians, military experts - all have to be skilled in calculating the probability of the events with which they are concerned.

[Gardner, 1986]


Probability theory is the branch of mathematics that tells us how to estimate degrees of probability. If an event is certain to happen, it is given a probability of 1. If it is certain not to happen, it has a probability of 0.

This course introduces the principles of probability and random processes to undergraduate students in electronics and communication. The topics to be covered include random experiments, events, probability, discrete and continuous random variables, probability density function, cumulative distribution function, functions of random variables, expectations, law of large numbers, central limit theorem, introduction to random processes, Gaussian random process, autocorrelation and power spectral density.


  • The (second) online self-evaluation form is due by the end of Dec 12.
  • Information regarding the final exam [Last Updated @ 10PM on Dec 10]
    • Date: 12 Dec 2017
    • Time: 9:00 - 12:00
    • ROOM: BKD 2501-2, 2506 and 2602
    • Basic calculators, e.g. FX-991MS, are permitted.
    • 9 pages ( including the cover page)
      • To save time, read the cover page posted here before going into the exam room.
    • 14+1 = 15 questions. (6+5+16+8+5+1+5+14+12+5+2+2+4+14+1)
    • Closed book. Closed notes.
    • Two A4 sheets allowed.
      • The first sheet is your midterm study sheet.
        • May add more formulas on the remaining side.
        • Q: Can I make a brand new study sheet?
          A: No.
          However, if you think the old one is in a bad shape (falling apart), you can use a photocopy of your own sheet. (Reduction in size is not allowed though)
        • Q: What can I do if I lose my study sheet?
          A: Dr.Prapun can print out a scanned copy for you. (The writing won’t be as crisp as the original one but it’s better than nothing.)
        • Q: I think the midterm study sheet (and the thing I wrote on it) is cursed (making me get poor score); I don’t want to see or use anything on it anymore. What can I do?
          A: You may bring a brand new sheet for the final exam. However, you can only use one side of it.
      • The second sheet must contain the Phi/Q tables
        • Distributed in class on Dec 7.
        • May reprint if necessary but do not reduce the size.
        • May add more formulas on the remaining side.
        • Indicate your name and ID on the upper-right corner of the sheet (in portrait orientation) on the handwriting side.
  • Slides for information about the midterm exam [Posted @ 1:30PM on Sep 27; Updated @ 4PM on Oct 9 and @ 2:30PM on Oct 10]
  • Information regarding the midterm exam [Posted @ 4PM on Sep 26]
    • Check this course website regularly for breaking news about the midterm.
    • Date: October 5, 2017 (Thursday)
    • TIME: 15:00-17:00
    • ROOMs: BKD 2506, 2501-2
    • Information about the midterm exam:
      • 7 pages (including the cover page)
        • To save time, read the cover page (to be posted) here before going into the exam room.
      • 10+1 = 11 questions. (10+5+4+10+8+8+8+9+3+1+1 = 67 pt)
      • Cover all the materials that we discussed in class and practice in the HWs.
        • Material Distribution (score-wise): 10 (CH1-2) + 27 (CH3-4) + 10 (CH5) + 19 (CH6)
    • Closed book. Closed notes.
    • (1 pt) One A4 page allowed.
      • Must be hand-written in your own handwriting.
      • No small pieces of paper notes glued/attached on top of it.
      • Indicate your name and ID on the upper right corner of the sheet (in portrait orientation).
      • Do not modify (,e.g., add/underline/highlight) content on the sheet inside the exam room.
      • Make sure that another side is blank. This will be used for the final exam.
      • Submit your A4 sheet with your exam. (You will get it back before the final exam.)
      • Q: I don't need any formulas. What should I do?
        A: Bring in and submit a blank sheet of paper with your name and ID. Note that you can still only use one side on the final exam.
      • Violating the above instructions will cost you 10 pt.
    • Basic SIIT-approved calculators, e.g,. FX-991MS, are permitted, but borrowing is not allowed.
    • For your studying pleasure....
  • We also have a Line group.
  • Note that we also share the tutorial/make-up session (Wednesday, 09:00-10:20, BKD2601) with ECS332.
  • This site can be accessed via ecs315.prapun.com.
  • Welcome to ECS315! Feel free to look around this site.

General Information

Handouts and Course Material

Problem Set

  1. HW 1 (Due: Sep 1)
  2. HW 2 (Due: Sep 7)
  3. HW 3 (Due: Sep 14)
  4. HW 4 (Due: Sep 21)
  5. HW 5 (Due: Sep 28)
  6. HW 6 (Not Due)
  7. Self-Evaluation Form (1) (Due: Oct 5)
  8. HW 7 (Due: Oct 19)
  9. HW8 (Due: Oct 31)
  10. HW9 (Due: Nov 9)
  11. HW10 (Due: Nov 16)
  12. HW11 (Due: Nov 23)
  13. HW12 (Due: Not Due)
  14. HW13 (Due: Not Due)
  15. Self-Evaluation Form (2) (Due: Dec 12)


Reading Assignment

  1. Section 1.2 in the lecture notes
  2. 2.5 in the lecture notes

More References

Misc. Links