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Welcome to Simulation of communication systems (DT001A) Magnus.Eriksson@miun.se and Filip.Barac@miun.se
A project course about MATLAB with SIMULINK and Communications Blockset… MATLAB = Matrix Laboratory. Tool for numerical calculation and visualization. Commonly used for simulation of the communication system physical layer, signal and image processing research, etc. SIMULINK: Toolbox in Matlab that allows graphical data-flow oriented programming.
Aim of the course • To prepare the student for thesis project and work in the area of telecommunciations development and research. • To give experience of performance analysis of communication systems and algorithms, at the physical layer and datalink layer. • To give experience of simulation tools such as MATLAB, SIMULINK and/or Opnet. • This may include modelling and simulation of traffic sources, channel models, modulation schemes, error coding schemes, equalizers, algorithms, protocols and network topologies. • A real-world project is studied within an application area such as wireless sensor networks, cellular communications, modems for broadband access, wireless networks, short-range communication, digital TV transmission, IP-TV or IP-telephony.
Prerequisites • Computer Networks A 7.5 ECTS credits or similar • Computer Engineering B, Wireless Internet access (most important!) • Computer Engineering AB-level, 30 ECTS credits • TCP/IP networking • Mathematical statistics • Programming Other helpful courses: • Transform theory, 7.5 ECTS credits. • Electrical engineering A, Analog electronics or Circuit theory • Electrical Engineering B, Telecommunications, 7.5 ECTS credits. • Electrical engineering B, Signals and systems, 7.5 ECTS credits. • Markov processes/Queueing theory
Litterature • Matlab, Simulink and Opnet documentation will be provided electronically. • Please repeat physical layer issues and datalink layer issues in basic books in Computer Networks and Wireless Internet Access.
Requirements • All lectures and supervision lessons are mandatory. • You are expected to devote 20 hours/week to this course. • Quzzes (multiple choice tests): At least 70% correct answers. • Lab: About 20 hours of work. • Homework problem. • Oral presentations. • Project
Requirements on the project Review at least one research paper, and describe some standard and some existing simulation model. Simulate a communications standard, or check the simulations made in a research paper. At least modify an existing simulation model, for exampel a Simulink or Matlab demo, or build a model of your own (more difficult) Produce some plots for several parameter cases, showing for example BER, bit rate or delay as function of at least two different parameters, for example SNR, facing model, modulation scheme, etc. The simulation results should be stable (the plots smooth and not jerky), i.e simulate sufficiently long simulation time, or take the average of sufficiently large number of simulations. Draw some interesting conclusions from this.
Grading is based on • Keeping deadlines. • Quzzes. • Showing good understanding when andwering questions from teachers and other students about your presentations. • Extent of own code. • Research relevance. • Own new results or conclusions.
Assignment 1: Theory repetition • The first assignment consists of old exam problems in Computer Networks A, Wireless Internet access B and Telecommunications B. • Deadline: Friday course week 2. Be prepared to present your answers on the whiteboard.
Assignment 2: Simulink lab exercize • Takes about 10-15 hours to do. • Deadline: Course week 3
Assignment 3: Present a standard and an existing simulation model Essentially chapter 2 (theory) and 3 (existing model that you start out from) of your report. Examples 802.11b PHY Simulink model 256 channel ADSL. IEEE 802.11a WLAN Physical Layer. Azhar Iqbal will look at 802.11n. Peter Burgos will look at 802.11ac. Bluetooth Voice Transmission. Majid Munir Bluetooth Full Duplex Voice and Data Transmission Digital Video Broadcasting Model (DVB-T). Also describe DVB-T2 and maybe DVB-H. Elijas. NFC (Simulink model by previous years students – see Mathworks file archive). CDMA2000 Physical Layer. WCDMA Coding and Multiplexing. WCDMA Spreading and Modulation WCDMA End-to-end Physical Layer. Ultrawideband (UWB/wireless USB). See mathworks file archive. Tobias ZigBee Simulink model. See mathworks file central. ZigBee Opnet model and Multihop routing protocols (Opnet model) . You may demonstrate simulink model (see Matlab file central) or Opnet model. Fredrik and Johan. Long-term evolution (LTE) Phy Downlink with spatial modeling: Jiahuan Lei, Wenxuan Jiang. Mention LTE-Advanced. Long-term evolution (LTE) and eMBMS: Jimmy and Jonas. Acoustic modem (new model) Acoustic QR code (continue on project by previous year’s students) 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.mdlThis 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.
Assignment 3 (cont.) Oral presentation: Course week 5. Talk 10-15 minutes per person. Everyone should take notes, and everyone should ask questions and discuss the topic. Present: A standard document New versions of the standard or ongoing development Screen dumps from an existing simulation Differences between simulation and full standard For higher grades: Also cite a related research paper or a textbook, for example a simulation method with results. See scholar.google.com or library. Within one week after that: Submit report chapter 2 (theory/previous research) and chapter 3 (existing model)
Assignment 4: Quizzes • Basic concepts, Matlab and Simulink concepts • Requirement: At least 70% correct answers. • You can do them over and over again until the deadline.
Assignment 5: Opnet lab • Zigbee and multihop simulation in Opnet. • Takes about 4 hours to do.
Assignment 6: Present project suggestion • Oral presentation course week 6. • Present • Problem formulation (chapter 1) – what to parameters to evaluate • Cite simulation done in a research paper (if you have not done so) • Planned own modification or development of model (chapter 4) • Submit or show report chapters 1 and 4 before christmas.
Assignment 7: Final project presentation • Demonstrate simulation code to teacher (and also in report appendice) • Oral presentation in mid-January of • Results (chapter 5): Plot performance for several cases. • Conclusions (chapter 6). Discuss similarities and differences from result in a cited research paper. • Provide a preliminary report when you give your oral presentation.
MATLAB MATLAB = Matrix Laboratory. Tool for numerical calculation and visualization. Commonly used for simulation of the communication system physical layer, signal and image processing research, etc.
This is how MATLAB looks like Workspace Commandhistory Command window
More MATLAB windows Figure window Array editor M-file editor
How to get help in MATLAB? help functionsname Shows unformatted text doc funktionsnamn Shows HTML documentation in a browser
SIMULINK SIMULINK: Toolbox in Matlab that allows graphical data-flow oriented programming.
Repetition of some basic concepts • Frequency spectrum • Digitalisation, source coding • Error coding • Modulation • Multiple-access methods • Base-band model • Distorsion, noise • Signal-to-noise ratio • Bit-error ratio • Statistics
AD-converter with seerial output DA- converter Interpolation filter Anti aliasing- filter Sampler 8 bit per sampel i.e. 64000 bps per phone call 28 = 256voltage levels PCM = Pulse Code Modulation = Digital transmission of analogue signals Number exemples from PSTN = the public telephone network 011011010001... 1 0 Loudspeaker Microphone 8000 sampels per sec 300-3400Hz band passfilter. Stopseverything over 4000Hz.
Layer 7 Digitalizatingcompression Source coding Source decoding Layer 6 0110 0110 Error management Error control . Layer 2 0110010 0100010 Bitfel Flow control Flow control Layer 1 Modulation Demodulation Point-to-point communication Mikrofon Högtalare NACK 0110010 ACK
Digital modulation methods Binary signal ASK = Amplitude Shift Keying (AM) FSK = Frequency Shift Keying (FM) PSK = Phase Shift Keying (PSK)
8QAM example: Below you find eight symbols used for a so called 8QAM modem (QAM=Quadrature Amplitude Modulation). The symbols in the first row represent the messages 000, 001, 011 and 010 respectively (from left to right). The second row representents 100, 101, 111 and 110.
Bit rate vs baud rate Bit rate in bit/s: Where M is the number of symbols and fs is the symbol rate in baud or symbols/s.
Figure 5.14The 4-QAM and 8-QAM constellations Q (Quadrature phase) Q (Quadrature phase) I (Inphase) I (Inphase)
Sine wave example Complex representation 5 Volt л/2 radians = 90º I
Inphase and quadrature phase signal • Sine wave as reference (inphase) signal: • Cosine wave as reference (inphase) signal:
Complex baseband representation jQ C =I+jQ Amplitude: Phase: RF signal (physical bandpass signal, if a cosine is reference signal): |C| C Arg C I