先進情報科学特別講義 Ⅱ,Ⅳ 高スループット無線通信システムに関する研究動向. Research Trends on High Throughput Wireless Communication Systems

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1 先進情報科学特別講義 Ⅱ,Ⅳ 高スループット無線通信システムに関する研究動向 Research Trends on High Throughput Wireless Communication Systems 1 Tran Thi Hong Computing Architecture Lab Room: B405

2 LECTURE INFORMATION Lecturer Assistant Prof. Tran Thi Hong, Computing Architecture Lab Slide I will upload lecture slides here: Score Pass ( 合格 ) Not Pass ( 不合格 ) Attend at least 3 classes Attend less than 3 classes Contact Room: B405 hong@is.naist.jp 2

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4 LECTURE CONTENTS Lecture 1+2: Fundamental of Communication System Lecture 3+4: Research Trends on High Throughput communication systems 4

5 5 FUNDAMENTAL OF COMMUNICATION SYSTEM

6 INTRODUCTION Medium channel: Mechanical wave Receiving data: Vibration frequency of particles Human ear: 20 Hz 20 KHz 6 Understanding information: languages (English, Japanese, etc.)

7 INTRODUCTION Ancient Systems: Smoke Signals Carrier Pigeons, etc. 7

8 INTRODUCTION Today System: Post Office Wired communication Wireless communication 8

9 INTRODUCTION Communication system is a system that send and receive the information. It provides electronic exchange of multimedia data, Voice, data, video, music, , web pages, etc. The frequency bandwidth occupied by the information signal is called the baseband, and the signal is often referred to as the baseband signal. Communication Systems of today Radio and TV broadcasting, Public Switched Telephone Network (voice, fax, modem) Cellular Phones Computer networks (LANs, WANs, and the Internet) Satellite systems (pagers, voice/data, movie broadcasts) Bluetooth 9

10 BASIC COMMUNICATION SYSTEM Source Transmitter Channel Receiver Destination Source of information Audio Video Image Data , etc. 10

11 BASIC COMMUNICATION SYSTEM Source Transmitter Channel Receiver Destination Convert information into suitable form for channel Modulator Amplifier Error Correction Encoder, etc. 11

12 BASIC COMMUNICATION SYSTEM Source Transmitter Channel Receiver Destination Detect and estimate the received signals Demodulator Amplifier Error Correction Decoder, etc. 12

13 BASIC COMMUNICATION SYSTEM Source Transmitter Channel Receiver Destination Computer Software program Speaker Monitor, etc. 13

14 BASIC COMMUNICATION SYSTEM Source Transmitter Channel Receiver Destination Medium used to transfer signal from TX to RX Wire cables Fiber optic cables Atmosphere (wireless): WLAN, WMAN, etc. LIFI (Light Fidelity) or VLC (Visible Light Communications) 14

15 WIRELESS COMMUNICATION SYSTEM Transmitting information using electromagnetic waves in open space (atmosphere) Electromagnetic wave Travel at speed of light (c = 3x10 8 m/s) Has a frequency (f) and wavelength (λ) c = f x λ Higher frequency means higher energy photons The higher the energy photon the more penetrating is the radiation 15

16 GENERATION OF ELECTROMAGNETIC WAVES When an alternating current (AC) passes through a copper conductor it generates radio waves which are propagated into the air using an antenna 16

17 GENERATION OF ELECTROMAGNETIC WAVES If charges oscillate back and forth get time-varying electric field time-varying magnetic field time-varying electric field. Finally, Electromagnetic field is generated. Note: magnetic fields are perpendicular to the electric fields. 17

18 GENERATION OF ELECTROMAGNETIC WAVES If charges oscillate back and forth or existing get timevarying electric field time-varying magnetic field timevarying electric field. Finally, Electromagnetic field is generated. Note: magnetic fields are perpendicular to the electric fields. 18

19 GENERATION OF ELECTROMAGNETIC WAVES 1 A flow of a high frequency electric current generates a magnetic field 2 The changing of Magnetic field electric field 3 The change of electric field magnetic field, etc. Antenna: copper wires + high frequency electric current 19

20 SEVERAL TYPES OF ANTENNAS 20

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22 PROPAGATION OF ELECTROMAGNETIC WAVES 22

23 PROPAGATION OF ELECTROMAGNETIC WAVES 23

24 PROPAGATION OF ELECTROMAGNETIC WAVES 24

25 PROPAGATION OF ELECTROMAGNETIC WAVES Electromagnetic waves are generated by an antenna and they propagate in all directions as a straight line Electromagnetic waves travel at a velocity of ~3x10 8 m/s Electromagnetic waves become weaker as they travel a long distance 25

26 ELECTROMAGNETIC SPECTRUM Radio waves: 3KHz ~ 300 GHz 26

27 TYPICAL WIRELESS COMMUNICATION SYSTEMS Wi-Fi (WLAN) a/b/g/n/ac Cellular WiMAX , e & f Bluetooth ( ) GSM,3GSM,GPRS,CDMA,CDMA 2000,CDPD (Cellular Digital Packet Data),TDMA, LTE, LTE Advanced Zigbee ( ) 27

28 TYPICAL WIRELESS COMMUNICATION SYSTEMS Satellite UWB (Ultra-Wide Band) Radar Miliwave communication 28

29 TYPICAL WIRELESS COMMUNICATION SYSTEMS 29

30 CELLULAR COMMUNICATION EVOLUTION 30

31 WIFI COMMUNICATION EVOLUTION GHz 5GHz 60GHz g 54 Mbps ax n (on working) a 600 Mbps ac 10 Gbps 54Mbps 6.9 Gbps ad 6.7 Gbps How the throughput can improved such significantly? Which technologies has been used? 31