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Visible Light Communications:
Recent Activities in Japan
Shinichiro Haruyama, Professor
The Graduate School of System Design and Management,
Keio University, Yokohama, Japan
Smart Spaces: A Smart Lighting ERC Industry - Academia Day
at BU Photonics Center, Boston University
February 8, 2011

Shinichiro Haruyama

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Contents
1. Visible light communication
2. Methods of visible light communication
3. Areas to which visible light
communication may be applied
4. Conclusion

Shinichiro Haruyama

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1. Visible light communication

Shinichiro Haruyama

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1. Visible light communication
Visible Light communication is a wireless communication
technology that uses light that is visible to humans.
Typical example of visible light communication: the use of LED illumination as a transmitter

LED Lights

Receiver

Why do we want to use visible light for communication?
Shinichiro Haruyama

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Reason 1: Visible light communication is not regulated.
Radio Wave and Light Wave
Frequency (Hz)

13
10
3THz 12
1THz 10
11
10
1010

Visible light
Infrared light

9
1GHz 10
108

Wireless LAN
Cellular phone
TV
FM radio

7
10
1MHz 106

Light Wave

Ultraviolet light

Radio Wave

16
10
15
10
1014

Visible light communication

Frequency above 3THz is NOT
regulated by the Radio Regulation
Law .

The use of radio frequency below 3THz
is regulated by the Radio Regulation
Law .

AM radio

Visible light communication is not regulated, so it is fairly easy to introduce new products , though safety regulation of high-power LED light has been already discussed. Shinichiro Haruyama

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Reason 2: Visible light LED will be used everywhere.
Infrared light is already used for communication, such as wireless remote control , IrDA, Infrared wireless LAN, and infrared interbuilding communication. However, visible light LEDs are beginning to be used in every home and office, which makes visible light LEDs ideal for ubiquitous data transmitter.

Data source: Nikkei Electronics

Prediction of LED lighting in the global market

Data source: OIDA

Prediction of market share of lighting types: SSL(Solid State Lighting or LED lighting), incandescent lamp, and fluorescent light

The growth rate of LED lighting is expected to triple from 2009 to 2012, and the market share of LED lighting will be more than 30 percent of total lighting market in 2016. Shinichiro Haruyama

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Reason 3: Image sensors can be used as receivers
The use of image sensors as receivers makes it possible detect not only incoming data, but also the accurate direction of the incoming vector from a transmitter to a receiver.
The image sensor technology will allow visible light
communication to various new applications as shown below,
which cannot be realized by radio wave technology:





Indoor navigation
Augmented reality
Accurate control of robots or vehicles
Accurate position measurement

Shinichiro Haruyama

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2. Methods of visible light communication
2.1. Devices used for Visible Light Communication
2.2. Communication using Image Sensors

Shinichiro Haruyama

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2.1. Devices used for Visible Light Communication

Visible Light

Transmitter device

Shinichiro Haruyama

Receiver device

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Transmitter device of visible light communication
-Visible light LED
LED light intensity is modulated by controlling
its current.
data rate: low speed to very high speed
(up to several hundred Mbps)

-Fluorescent lamp
FSK modulation of high frequency fluorescent light
data rate: up to several kilo bps

Shinichiro Haruyama

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Receiver device of visible light communication
-PIN photo diode
-high speed reception up to 1Gbps

-Avalanche photo diode

-very sensitive reception

-Image sensor
-simultaneous image acquisition and data reception
Shinichiro Haruyama

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2.2. Communication using Image Sensors

Data can be received with...
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