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Assignment 4:

Describe a communication system and

demonstrate a simulation model of it

In this assignment you should choose an existing simulation model of a communications system, and demonstrate it. It may be a Simulink model, or a Matlab toolbox. Search among the Matlab demos, or among freeware Simulink models that people have uploaded to

www.mathworks.com/matlabcentral/.

You should also briefly describe the features and principles of operation of this telecommunication system, and give facts and figures about the protocol or standard. See the list of telecommunications references in the course material folder. You may start out by reading about it in an online encyclopedia. Try to find the original protocol standard document. Alternatively you may borrow a book in the library that describes the standard, or search on the internet for a “white paper” or a “survey” on this standard.

You may discuss how the Simulink or Matlab model differs from the standard or from reality. What simplifications are made in the model of the system? For example, data link layer issues may be omitted, power control may be skipped in a cellular system, only certain modes may be simulated, fading and co-channel interference may be omitted in the modulation, and if no fading is included in the channel model, an equalizer may be omitted.

This is also your choice of project topic for the rest of the course. Later on in this course, you should develop a Simulink model or make some minor modifications to an existing model, and analyze the simulation results.

If several course participants are choosing the same model, you have to work in a group. A group size of two is recommended, but one and three are allowed.

The grading of the final project will be based on:

- If you keep the deadlines.

- How difficult or large project you choose.

- The depth of the theory study (math formulas and good understanding of the features and principles of operation is advantageous)

- Programming skills

- Problem definition, problem analysis and analysis of the results

- Report language, layout and structure

- Oral presentation

A. Choice of project

Publish a message in the discussion forum “Project” as soon as possible, where you state your choice of communication system as well as model to start out from. NB! The message should start a new thread, and should not be a reply to a previous message. The title of the message should be the name of the communications system or the model that you have chosen. During the rest of the course, you will publish all documents related to your project in this thread. Your fellow students and supervisor may publish comments questions and suggestions related to your project in the same discussion thread.

Here are some suggestions for project topics:

1. 256 channel ADSL.*

2. IEEE 802.11a WLAN Physical Layer. *

3. Bluetooth Voice Transmission.*

4. Digital Video Broadcasting Model. *

5. CDMA2000 Physical Layer. *

6. WCDMA Coding and Multiplexing. *

7. WCDMA Spreading and Modulation *

8. WCDMA End-to-end Physical Layer. *

10. Bluetooth Full Duplex Voice and Data Transmission **

11. RUNE – Rudimentary cellular Network Emulator. (Toolbox consisting of .m-files.). Simulation of handover, power control and other radio resource management schemes in a cellular system. I will provide you with the toolbox files, which are delivered with the book “Radio Resource Management for Wireless Networks” by Jens Zander.

12. Line codes. Comparison of RZ, NRZ, AMI, Manchester coding (used in 10 Mbps Ethernet), 4B5B (used in 100Base-TX Ethernet) and PAM5 (used in 1000Base-T Gigabit Ethernet): For a code demonstrating RZ, NRZ, AMI and Manchester, see
http://apachepersonal.miun.se/~rogols/teaching/mks/lab2/LineEncoding.mdl
This code also requires this MATLAB function:
http://apachepersonal.miun.se/~rogols/teaching/mks/lab2/line_encoder.m . During the rest of the project you may further develope the code to deal with 4B5B and PAM5, and to measure the bit error rate.

12. 802.11b PHY Simulink model **

13. Ultrawideband (UWB/wireless USB) Fixed-point model **

14. Ultrawideband (UWB/wireless USB) Channel model. **

15. Modulated sound: This project will be about transferring digital data as modulated sound, using a loudspeaker and a microphone. The idea is that students should evaluate differens modulation and error coding schemes. The model should also include an equalizer and a synchronization scheme, and perhaps spread spectrum. During your first presentation you may just present the standard digital modulation system Simulink demo, which is a good starting point. I might also provide you with a code that some students developed a few years ago.

*) See "demo" in Matlab.

**) See Matlab Central.

I have not tested all of them yet, you have to do that. A majority of them should work in our environment.

B. Oral presentation

During the seminar in week 8, give a short demonstration of the model and present the most essential facts about the communication system that you have chosen orally. You may for example present a block schedule, a table that summarizes the features of the model, and a list of some key terms with short definitions. See below. You may talk for 5 to 10 minutes per group member.

C. Publish chapter 2, the system description

Write chapter 2 of the report, which is a short theory study, a description of a communication system. Publish it in ”your” discussion thread (see above) in the discussion forum ”Project”, by the end of week 8. This chapter may include one to three pages of text per group member. Use the MS Word template that can be found in the course materials folder.

The text should review at least one reference, for example the original standard document. It should include a system overview illustration, for example a block schedule. You may describe the most important blocks briefly. Focus on the blocks that are included in the Simulink model. A table that describes the most important figures and technical parameters is recommended, for example bit rates, frequencies, bandwidth, transmission power, modulation schemes, symbol rates, number of OFDM or OFDMA subcarriers, error codes, bit interleaving schemes, multiple access schemes (FDMA, TDMA, CDMA-DS, Frequency hopping, CSMA/CA, etc), source coding protocols, etc. You should also say a few words about the area if application. Define all terms that you use as pedagogical as possible. It should be understandable to your fellow students.

Chapter 2 is written before Chapter 1, the introduction, since it is easier to formulate a good problem statement in the introduction chapter after you have understood the basic features of the system that you intend to analyze.

NB! Chapter 2 should not describe the simulation model, but the communication standard, with a certain emphasis on the parts that are included in the model. The simulation model may be a simplified special case, for example point-to-point communication, restricted to certain protocol layers. The model simplifications, limitations and basic assumptions, as well as the changes to it that you intend to carry out, should be described in chapter 3, the model chapter, later in the course.