Wireless Communication Systems IK2507

1. Wireless Communication SystemsIK2507 Anders Västberg vastberg@kth.se 08-790 44 55

2. IK2507 Wireless Communication Systems • Aim • The course aims at providing basic knowledge about problems and design approaches in wireless communication systems. • This includes engineering models in radio propagation and the application of antennas to wireless communication. • An introduction to spectrum resource management issues is also given in the course.

3. IK2507 Wireless Communication Systems • 12 Lectures, 2 h each • 12 Recitations, 2 h each • 2 labs, 4 h each • Homework • Gives bonus points to exam

4. Teachers • Anders Västberg – Lectures • vastberg@kth.se, 08-790 44 55 • Göran Andersson – Recitations • goeran@kth.se • Ali Özyagci – Labs • ozyagci@kth.se

5. Course Material • Required reading: • Ahlin et. al., Principles of Wireless Communications, Studentlitteratur, 2005. • Recommended: Råde and Westergren, Beta, Mathematical Handbook for Science and Engineers, Studentlitteratur. • Course Webpage: • http://www.kth.se/student/program-kurser/kurshemsidor/ict/cos/IK2507/HT10-1 • Contains solutions to selected problems • Old exams with solutions • Lecture notes • Lab manuals

6. Requirements • TEN1: 6 hec. • A part theory, B part problems • One homework problem which gives 1.5 p bonus to the B part. • A-F grade • LAB1: 1.5 hec. • Two labs: • Radio PlanningPropagation • Prediction and Planning for Cellular Systems. • P/F grade

7. Final Exam • Part A: 7 questions of 1 point each (closed book) • Part B: 5 questions of 3 points each (open book) [Slimane, 2009]

8. Ahlin et. al., Principles of Wireless Communciations • Chapter 1: Introduction • Chapter 2: Propagation • Chapter 3: Wireless Link Design • Chapter 5: Diversity Systems • Chapter 7: Multi-User Communications • Chapter 9: Wireless Networks

9. Radio Communication • Radio or radio communication means any transmission, emission, or reception of signs, signals, writing, images, sounds or intelligence of any nature by means of electromagnetic waves of frequencies lower than three thousand gigacycles per second (3000 GHz) propagated in space without artificial guide. • Examples of radio communication systems: • Radio broadcasting. • TV broadcasting. • Satellite communication. • Mobile Cellular Telephony. • Wireless LAN. • Multimedia communication & Mobile Internet [Slimane]

10. History • 1864: Maxwell describes radio wave mathematically • 1888: Hertz generates radio waves • 1890: Detection of radio waves • 1896: Marconi makes the first radio transmission • 1915: Radio tubes are invented • 1948: Shannon’s law • 1948: Transistor • 1960: Communication Satellites • 1981: Cellular technology

11. Classification of radio spectrum

12. The Radio Spectrum • The frequency spectrum is a shared resource. • Radio propagation does not recognize geopolitical boundaries. • International cooperation and regulations are required for an efficient use of the radio spectrum. • The International Telecommunication Union (ITU) is an agency, within the UN, that takes care of this resource. • Frequency assignment. • Standardization. • Coordination and planning of the international telecommunication services. [Slimane]

13. Evolution of Wireless Systems [Stallings., 2005]

14. Evolution of Cellular Systems AMPS USDC IS-136 CDPD TD-SCDMA ETACS GSM GPRS EDGE WCDMA NMT CDMA IS-95 CDMAone IS-95B CDMA2000 1G 2G 2.5G 3G [Slimane]

15. LTE-Long Term Evolution • High spectral efficiency • Very low latency • Support of variable bandwidth • Simple protocol architecture • Simple Architecture • Compatibility and inter-working with earlier 3GPP Releases • Inter-working with other systems, e.g. cdma2000 • FDD and TDD within a single radio access technology

16. Other Technologies • WLAN • Bluetooth • Sensor networks (Zigbee and IEEE 802.15.4)

17. Radio Communication • Three main problems: • The path loss • Noise • Sharing the radio spectrum

18. Challenges Today • The Revenue Gap • Flat rate models for wireless broadband increase the demand for bandwidth but do not increase revenue. • Cost is roughly proportional to bandwidth • Energy Consumption • Energy consumption of the ICT industry is roughly 2% • Communication is increasing rapidly • Energy cost is also increasing

19. Communication Systems Message signal Source of information Transmitter Transmitted signal Channel + Noise & Interference Estimate of message signal Received signal Receiver Information sink [Ahlin et. al., 2006]

20. Analog Communication System Source of information Signal Processing Modulator RF-Stage Channel Information sink Signal Processing Demodulator RF-Stage [Slimane]

21. Digital Communication System Source of Information Source Encoder Channel Encoder Digital Modulator Modulator RF-Stage Channel Information Sink Source Decoder Demodulator RF-Stage Channel Decoder Digital Demodulator [Slimane]

22. decibels • The bel is a logarithmic unit of power ratios. One bel corresponds to an increase of power by a factor of 10 relative to some reference power, Pref. • The bel is a large unit, so that decibel (dB) is almost always used: • The above equation may also be used to express a ratio of voltages (or field strengths) provided that they appear across the same impedance (or in a medium with the same wave impedance): [Saunders, 1999]

23. decibels [Saunders, 1999]