光無線通信Optical Mobile Communication

光無線通信の歴史

800BC Fire beacons – by ancient Greeks and Romans

150BC Smoke signals – by American Indians

1790s Optical telegraph – by Claude Chappe, France

1880 Alexander Graham Bell demonstrated

the photophone-First FSO

1960s

Invention of laser (revolutionized FSO), and optical fibre FSO

mainly used in secure military applications

1970s 1979

Indoor OWM systems – F R Gfeller and G Bapst

F. R. Gfeller and U. Bapst, “Wireless in-house data communication via diffuse infrared radiation,” Proc.

IEEE. 67(11), 1474–1486 (1979)

1993

Open standard for IR data communication – The Infrared Data

Association (IrDA)

2003

The Visible Light Communications Consortium (VLCC) – Japan

2008

Develop global standards for home networking (infrared and

VLC technologies) – “hOME Gigabit Access” (OMEGA)

Project – EU

2009

IEEE802.15.7 – Call for Contributions on IEEE802.15.7 VLC.

光無線通信の歴史

4

光多元アクセス方式

Station A

Fixed Reflector Array

Optical Wireless HeadStation B

Station C

Hub Station

Rotating Reflector

Remote Station

Fixed Reflector C

Fixed Reflector A

Fixed Reflector B

Motor

AD/TDMA ;

Angle Division/Time Division

Multiple Access

Optical Wireless Head

5

Motor

Controller

Optical Wireless

Head

Stepping

Motor

Fixed Reflector

Array

Rotating

Reflector

Fixed Reflector

Array

Rotating

Reflector

AD/TDMA experiment devices

Optical transmitter

Operation device

6

User1User2User3 Phase shift

User1

User2

User3

Baseband Signal Generator

Beam forming

RF subcarrier

Frequency

光ビームホーミング

DOA(Direction Of Arrival,) estimate

7

Objective

• Security Improvement

• Need both I and Q for demodulation

Application

• Government sectors

• Very Important Persons (VIPs)

空間的な光無線信号合成による場所限定通信

Diagram

光ＲＦＩＤ

• Confidential Information is transmitted by OWC

• Employ energy harvesting during reader interrogation periods

8

E-passport

Identification Card, Driver License

Application

RFIDReader

MatchingRectifier

Energy Storage

Laser

ReaderTag

lensImage

Sensor

CCR

Energy

P1

… Pl

Pl+1 … Pk

Pk

P2

P1

…

Rx Data

Pk

P2

P1

…

Tx Data

Modulate the optical signal reflected from CCR

Small size (~200 µm)

Low power consumption (~19 pJ/bits)

Corner Cube Retroreflector

(CCR)

I want to find a car parkand know the price,position and if it hasempty slot now

I want to know theinformation of theaccident ahead

communication service

9

RF signal RF signal

RF transmitter

RF signal

Optical

signalRF signal

Optical

signalOptical

signal

Optical

signal

Optical

signal

Optical

signalOptical

signal

RF signalRF signal

A

1A

2

A

3

B

1

B

2

B

2

Proposed System

10

Receiving code A

Receiving Radio Signal

Optical signal

(CDMA code A)

RF signal

Welcome to Tokyo City

Optical

channel

RF

channel

RF signal

No optical

signal

RF signal

Optical signal

(CDMA code B)

No optical signal

Infrastructure network

Internet

Parking place 50m ahead 2 dollar/h

Receiving code B

DemodulateUse code A

to demodulate

Use code B

to demodulate

Proposed System

11