Welcome to Simulation of Telesystems (DTAC29), or Telesystems (ETAC52)

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1 Welcome to Simulation of Telesystems (DTAC29), or Telesystems (ETAC52) Magnus.Eriksson@miun.se

2 A project course about Matlab with Simulink and Communications Blockset

3 Aim of the course To prepare the student for thesis project and work on development of and research on today’s and tomorrow’s telecommunication systems. 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 and SIMULINK. This may include modelling and simulation of traffic sources, channel models, modulation schemes, error coding schemes, equalizers, algorithms and protocols. A real-world project is studied within an application area such as cellular communications, modems for broadband access, wireless networks, short-range communication, digital TV transmission, IP-TV or IP-telephony.

4 Prerequisites The course Computer Engineering B, Wireless Internet access, or Electrical Engineering B, Telecommunications, 7.5 ECTS credits. Mathematical statistics and transform theory, 7.5 ECTS credits. Computer Engineering or Electrical Engineering AB- level, 30 ECTS credits Computer Networks A 7.5 ECTS credits Program design in C++ or Java. It is also recommended that the student has studied Electrical engineering B, Signals and systems, 7.5 ECTS credits.

5 Preliminary schedule Week 4 Wed 060125 10:15-12:00 L408 Introduction lecture Week 5 Tue 060131 13:15-17:00 L320 Intro to Simulink. Lab exersize. Presentation of assignment 1. Week 6 Wed 060208 10:15-12:00 L320 Student seminars. Week 7 Tue 060214 10:15-12:00 L320 Student seminars. Week 8 Thu 060223 13:15-15:00 L320 Project supervision Week 9 Wed 060301 13:15-15:00 Ei3TeProject supervision Week 11 Wed 060315 10:15-12:00 L320 Project supervision Week 12 Mon 060320 10:15-12:00 L408 Project presentations Course details, list of assignments and final schedule will be provided within a few days, when we know the number of registered students. You are expected to devote 4 hours/week to this course, for example in L320. All scheduled events are mandatory. Answering deadlines in time is required for higher grades than approved.

6 Assignment 1: Theory repetition The first assignment consists of old exam problems in Computer Networks A, Wireless Internet access and Telecommunications B. It will be provided at Thursday (26/1) at WebCT to registered students. Please contact me by email if you are not registered yet, but want the assignment. Deadline: The second lecture (Tuesday week 5). Be prepared to present your answers on the whiteboard.

7 Repetition of some basic concepts

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9 PCM = Pulse Code Modulation = Digital transmission of analogue signals Sampler AD-converter with seerial output 011011010001... DA- converter Anti aliasing- filter Interpolation filter Sifferexempel från PSTN = publika telefonnätet: 300-3400Hz band pass filter. Stops everything over 4000Hz. 8000 sampels per sek 8 bit per sampel i.e. 64000 bps per phone call 2 8 = 256 spänningsnivåer 0 1 Microphone Loudspeaker

10 Effect of attenuation, distortion, and noise on transmitted signal.

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12 Felhantering med hjälp av felrättande koder FEC = Forward Error Correction. Baseras på felrättande istället för felupptäckande koder. Kräver ingen backkanal. Två typer: 1. Faltningskoder (convolutional codes). Ex:Vid Faltningskod med kodtakt (code rate) 1/3 infogas två redundanta bitar mellan varje bit i nyttomeddelandet. Dessa felrättande bitar beräknas kontinuerligt för varje inkommande bit i nyttomeddelandet. 2. Blockkoder (block codes) Ex: I digital-TV-systemet används en s.k. Read Salomon-kod med beteckningen RS(204, 188, 8). Det innebär att nyttoinformationen delas upp i 188 byte stora block. För varje block beräknas en felrättande kod, som läggs till blocket så att blocket blir 204 byte. Redundanden är alltså 204 – 188 = 16 byte. Koden klarar 8 felaktiga byte.