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

Tran Thi Hong

Computing Architecture Lab

Room: B405

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LECTURE INFORMATION

Lecturer

Assistant Prof. Tran Thi Hong, Computing Architecture Lab

Slide

I will upload lecture slides here: http://arch.naist.jp/~hong/

Score

Contact

Room: B405

Email: hong@is.naist.jp2

Pass (合格） Attend at least 3 classes

Not Pass （不合格） Attend less than 3 classes

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LECTURE CONTENTS

Lecture 1+2: Fundamental of Communication System

Lecture 3+4: Research Trends on High Throughput

communication systems

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FUNDAMENTAL OF COMMUNICATION SYSTEM

5

Medium channel: Mechanical wave

Receiving data: Vibration frequency of particles

Human ear: 20 Hz 20 KHz

Understanding information: languages (English, Japanese, etc.) 6

INTRODUCTION

INTRODUCTION

Ancient Systems:

Smoke Signals

Carrier Pigeons, etc.

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INTRODUCTION

Today System:

Post Office

Wired communication

Wireless communication

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INTRODUCTION

• Communication system is a system that send and receive the information.

• It provides electronic exchange of multimedia data, Voice, data, video, music, email, 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)

• Bluetooth9

BASIC COMMUNICATION SYSTEM

Source Transmitter Receiver Destination Channel

Source of information

Audio

Video

Image

Data

Email, etc.

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BASIC COMMUNICATION SYSTEM

Source Transmitter Receiver Destination Channel

Convert information into suitable form for

channel

Modulator

Amplifier

Error Correction Encoder, etc.11

BASIC COMMUNICATION SYSTEM

Source Transmitter Receiver Destination Channel

Detect and estimate the received signals

Demodulator

Amplifier

Error Correction Decoder, etc.

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BASIC COMMUNICATION SYSTEM

Source Transmitter Receiver Destination Channel

Computer

Software program

Speaker

Monitor, etc.

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BASIC COMMUNICATION SYSTEM

Source Transmitter Receiver Destination Channel

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)

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Transmitting information using electromagnetic

waves in open space (atmosphere)

Electromagnetic wave

Travel at speed of light (c = 3x108 m/s)

Has a frequency (f) and wavelength (λ)

Higher frequency means higher energy photons

The higher the energy photon the more penetrating is

the radiation

c = f x λ

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WIRELESS COMMUNICATION SYSTEM

When an alternating current (AC) passes

through a copper conductor it generates radio

waves which are propagated into the air using an

antenna

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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.

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GENERATION OF ELECTROMAGNETIC WAVES

If charges oscillate back and forth or existing 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.

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GENERATION OF ELECTROMAGNETIC WAVES

①A flow of a high frequency electric current generates a

magnetic field

②The changing of Magnetic field electric field

③The change of electric field magnetic field, etc.

Antenna: copper wires + high frequency electric current

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GENERATION OF ELECTROMAGNETIC WAVES

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SEVERAL TYPES OF ANTENNAS

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22

PROPAGATION OF ELECTROMAGNETIC WAVES

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PROPAGATION OF ELECTROMAGNETIC WAVES

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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 ~3x108 m/s

Electromagnetic waves become weaker as they travel a

long distance

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PROPAGATION OF ELECTROMAGNETIC WAVES

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ELECTROMAGNETIC SPECTRUM

Radio waves: 3KHz ~ 300 GHz

TYPICAL WIRELESS COMMUNICATION SYSTEMS

Wi-Fi (WLAN)

Cellular

WiMAX

Bluetooth (802.15.1)

Zigbee (802.15.4)

GSM,3GSM,GPRS,CDMA,CDMA

2000,CDPD (Cellular Digital

Packet Data),TDMA, LTE, LTE

Advanced

802.16 2004, e & f

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802.11a/b/g/n/ac

Satellite

Radar

UWB (Ultra-Wide Band)

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Miliwave communication

TYPICAL WIRELESS COMMUNICATION SYSTEMS

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TYPICAL WIRELESS COMMUNICATION SYSTEMS

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CELLULAR COMMUNICATION EVOLUTION

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WIFI COMMUNICATION EVOLUTION

1997 2003 2008 2014

2.4GHz

5GHz

60GHz

802.11a

54Mbps

802.11n

600 Mbps 802.11ac

6.9 Gbps

802.11ad

6.7 Gbps

802.11g

54 Mbps 802.11ax

(on working)

10 Gbps

How the throughput can improved such significantly?

Which technologies has been used?