In less than three decades, the status of cellular telephones has moved from laboratory breadboard via curious luxury item to the world's most pervasive consumer electronics product. Even though wired telephony is 100 years older and the beneficiary of "universal service" policies in developed countries, the number of cellular phones has exceeded wired phones for a few years and the difference keeps growing. For hundreds of millions of people in developing countries, cellular communications is the only form of telephony they have experienced.


This course provides an introduction to mobile communications system principles, design and technology. It also covers state-of-the-art topics such as LTE (SC-FDMA).


  • Annoucement slides are updated.
  • Information regarding the final exam
    • Date: 4 Mar 2011 (Friday)
    • Time: 9AM – 12PM
    • Room: BKD 3206
    • More information will be posted here.
    • Cover page
    • 12 Pages, 15 Questions
    • Cover all the topics that were presented in lectures/HWs.
    • Provided formulas
    • One shared formula sheet.
      • Copies of this sheet will be distributed in the exam room.
  • Information regarding midterm exam
    • Date: 24 Dec 2010
    • TIME: 09:00 - 12:00
    • ROOM: BKD 3206
    • Closed book. Closed notes. No cheat/study sheet.
    • Basic calculator allowed
    • Provided formulas
    • Cover page
    • Material: Ch1 20%, Ch2 65%, Ch3 15%.
    • Exam from previous year.
    • Scores. The leftmost column shows the last three digits of your ID.
  • Tuesday lecture is moved (again) to 2:40PM. We will meet at this new time starting on November 23.
  • Welcome to ECS455! Feel free to look around this site. [Posted @ 11AM on Nov 3]

General Information

Handouts and Course Material

  • Slides: Introduction to ECS455. (Updated on Nov 14)
  • Slides from previous year are posted to give you a sneak preview of the up-coming class meterial
Ch Handouts & Slides

Problem Set

  Due Date Remarks/Solutions
HW1 Nov 23 Solution
HW2 Dec 14 @ 2:39 PM Solution
HW3 Dec 21 @ 2:39 PM

You will use discrete time approximation to simulate Poisson process for the call requests and the exponentially distributed call durations. At the end of the assignment, you will compare the blocking probability that you evaluate from this model with the answer provided by the Erlang B formula.

For Q1.f, assume that the W_i are i.i.d. exponential random variables. The expected value for each of them is 1/lambda. (This fact will be discussed in lecture 12. You may read about it in the posted notes on PP.)

Solution + MATLAB Code

Self-Evaluation form (1) Jan 4 @ 2:39 PM  
HW4 Jan 18 @ 2:39 PM Solution
HW5 Feb 15 @ 2:39 PM Solution
HW6 Feb 25 @ 10:39 AM Solution
Self-Evaluation form (2) Mar 2 @ 12:00 PM  



Reading Assignment

  1. [T&V] Intro of Ch 2
  2. [T&V] Intro of Sec 2.1
  3. [T&V] Section 2.1.1, 2.1.2, 2.1.6
  4. [T&V] Intro of Sec 2.2,
  5. [T&V] Section 2.2.1, 2.2.2

Course Outline

  1. Review: Fourier transform and basic communication systems
  2. Cellular communications, Principles of cellular radio
    • Wireless Channel (Part 1)
    • Spectrum Allocation
    • Frequency Reuse and Sectoring
    • Trunking Theory and Erlang B formula
    • Poisson Process with review of basic probability theory
    • Markov Chain
      • The "best" introductory textbook on Markov chain is probably the one written by Norris. This again will be an overkill for this class but it serves as a good reference if you want to dig into this topic further. There are some sample chapters available on the web as well.
      • Whitt wrote an article that provide several remarks on Erlang B formula via a number of HW exercises. Those who want to read more about Erlang B study may find it interesting.
  3. Duplexing: TDD vs FDD
  4. MIDTERM:24 Dec 2010 TIME 09:00 - 12:00
  5. Multiple access schemes
  6. Spread Spectrum Communications
  7. Multi-carrier and OFDM systems
    • Wireless Channel (Part 2), multipath propagation and Equalization
    • Multi-carrier transmission and frequency division multiplexing
    • Orthogonality (revisited)
    • DFT and FFT
    • Oversampling
    • Cyclic Prefix and circular convolution
    • For deeper understanding of OFDM, please read
    • OFDMA
  8. GSM, GPRS, EDGE, UMTS (W-CDMA) and OVSF code
  9. WiMAX and OFDMA
  10. LTE and SC-FDMA
  11. FINAL: 4 Mar 2011 TIME 09:00 - 12:00

Misc. Links