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).


  • Final exam information
  • Scores for all HWs and quizzes are posted. [Posted @ 9:00PM on Mar 7]
  • Solutions for quiz 2, 3, 4, 5 are posted.
  • Self-evaluation form is posted. [Posted @ 11:00PM on Feb 23]
  • All of those who took quiz 4 got 10/10. [Posted @ 12:50PM on Feb 2]
  • The scores Quiz 2 are posted. [Posted @ 9AM on Jan 26]
  • HW5 is posted. Due Feb 5, 2010. [Posted @ 9:30AM on Jan 19]
  • HW4 is posted. Due Jan 12, 2010. [Posted @ 3:30PM on Jan 5]
  • Solution of the midterm is posted. [Posted @ 9AM on Dec 30]
  • Midterm scores are posted. [Posted @ 9AM on Dec 30]
  • The scores for HW1, HW2, and Quiz 1 are posted. The leftmost column shows the last three digits of your ID.
  • Midterm exam information
    • Date: 22 Dec 2009
    • TIME: 09:00 - 12:00
    • ROOM: BKD 2602 & BKD 2605
    • Material: Lecture 1 up to and including lecture 13
    • A combined version of the pre-midterm slides are posted as slides for lecture 14.
    • The following formulas are provided.
    • The first page of the exam is posted.
    • There will be an extra review session (in Thai) for those who can't completely catch the review that I made in lecture 14 because it is in English. There will not be any new information or examples given. It will be on Monday December 21 @ 4:35 PM.
      • Room: BKD: 3206 (same room as Microwave exam)
    • I will be in my office on Monday the whole day to answer any exam-related questions.
  • All of those who took quiz 1 got 10/10. [Posted @ 5:30PM on Dec 15]
  • HW3 is posted. [Posted @ 10AM on Dec 8]
  • Appendix A.1 of Rappaport (1995) is posted on the SIIT online lecture note system[Posted @ 9AM on Nov 30]
  • For Tuesday lecture (lecture 10), please read Appendix A.1 of Rappaport before you come to class. [Posted @8AM on Nov 30]
  • HW typo: There should be a factor of 1/2 in the exponent of the Rayleigh pdf. [Posted @11AM on Nov 26]
  • HW2 is posted on the SIIT online lecture note system[Posted @ 9AM on Nov 19]
  • The Tuesday lecture will be in the room BKD 3216 starting today. [Posted @ 8:30AM on Nov 10]
  • A lousy RSS feed for this page is created. All changes to the content below should be reported by the feed. [Posted @ 10:22AM on Nov 4]
  • HW1 is posted! [Posted @ 10AM on Nov 4]
  • Welcome to TCS455! Feel free to look around this site. [Posted @ 11AM on Oct 22]

General Information

Handouts and Course Material

Problem Set

  1. HW1 is posted on the SIIT online lecture note system
    • This HW forces you to review properties of Fourier transform. Some materials are discussed in Lectures 2 and 3.
    • Solution
    • Question 1b was graded.
  2. HW2 is posted on the SIIT online lecture note system
    • Read the last question carefully. We don't cover it in lecture but it will be useful later on.
    • Typo: There should be a factor of 1/2 in the exponent of the Rayleigh pdf. Thank you aRm for pointing this out. The MATLAB code already has this factor; so there is no need to change that. A new version of HW2 is posted to address this fix.
    • Solution: Question 1-6
    • Question 4 was graded.
  3. HW3
    • This assignment asks you to use MATLAB to verify the Erlang B formula.
      • Here 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 have in this model with the number from the Erlang B formula.
      • You will also see how random variables are generated and analyzed in MATLAB.
    • Caution: The variable A in question 1.d.ii and 1.d.iii is not the same as the variable A in the Erlang B formula.
    • Solution
  4. HW4
  5. HW5
  6. HW6 (fixed)
    • Partial Solution.
    • Submission is needed for grad students.
    • All students should try to work on this HW. It will give you a better understanding of OFDM.


Reading Assignment

  1. Chapter 1
  2. Chapter 3: 3.1 – 3.2, 3.5.1, 3.6, 3.7.2
  3. Appendix A.1 (Erlang B)
  4. Chapter 9: 9.1-9.5
  5. Theory of PN Codes from [Karim and Sarraf, W-CDMA and cdma2000 for 3G Mobile Networks, 2002]
  6. Section 1.2 from [Bahai, Multi-carrier Digital Communications: Theory And Applications Of OFDM, 2002]

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
  3. MIDTERM: 22 Dec 2009 TIME 09:00 - 12:00
  4. Duplexing: TDD vs FDD
  5. Multiple access schemes
    • FDMA
    • TDMA
    • CDMA (Part 1)
    • SDMA
  6. Spread Spectrum Communications
    • DSSS and m-sequences
    • CDMA (Part 2) and orthogonality, Walsh sequences and Hadamard Matrix
    • IS-95
    • FHSS
    • GPS and Gold codes
  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
    • OFDMA
  8. GSM, GPRS, EDGE, UMTS (W-CDMA) and OVSF code
  9. WiMAX and OFDMA
  10. LTE and SC-FDMA
  11. FINAL: 9 Mar 2010 TIME 09:00 - 12:00

Misc. Links