2D Image Transmission using
Light Fidelity Technology
Vyom Shah , Disha Purohit , Prajakta Samant , Ruhina Karani
Undergraduate Student , Computer Engineering Department
Dwarkadas J. Sanghvi College of Engineering, Mumbai, India.
vyomshah1693@gmail.com, dishaa19@gmail.com, prajaktansamant@gmail.com, ruhina.karani@gmail.com.
Abstract : Recently wireless technology has
bloomed to a great extent we require wireless
technology to transmit a lot of data every day.
Nowadays, wireless communications has become
important in communication process. The main way
we transmit wireless data is by using
electromagnetic waves i.e. radio waves. However,
radio waves can support less bandwidth because of
compact spectrum availability and intrusion.
Solution to this is data transmission using Visible
Light Communication (VLC). Wi-Fi deals with
wireless coverage within premises, whereas Li-Fi is
perfect for high compactness wireless data coverage
in defined area and for mitigating radio interference
issues. In Li-Fi basically we focus to transmitting
multimedia data between two terminals using
LED’s.
Keywords : Wi-Fi (Wireless Fidelity), Li-Fi (Light
Fidelity), VLC (visible light communication), LED
(light emitting diode).
I.
INTRODUCTION
In 21st century communication between two
terminals is very important and takes place on every
day. Li-Fi plays an important role is communication
as discussed earlier which uses light for data
transmission instead of radio waves used in wireless
communication. The speed of data transmission was
about 10 mbps, though Dr. Haas is aiming to have it
reach 100 mbps[1].
Figure 1: Beam of LED’s
Wireless communication which uses[5] radio waves
for data transmission and communication between
terminals proves fatal in areas like oil petroleum
which can harm the environment causing vast
destruction so to avoid such situation using of light
in some area proves beneficial. Li-Fi is more secure
as it does not allow data leakage[2].
II.
Proposed System
Li-Fi technology consist of transmission of data
using light . So the proposed system has LED’s
which is useful for data transmission and implement
the basic concept of Li-Fi. It is divided into two
modules Transmitter and Receiver.
i.
Transmitter
Figure 2: Transmitter working
On the transmitter side the terminal which is the PC
used should contain MATLAB software which will
help us in converting the image into its binary
format and later transmitting the binary conversion
to the receiver via LED. Next is the USB to TTL
which is used so deal the communication of a
microcontroller. And microcontroller helps to
generate square wave form the binary converted
image by MATLAB and inputs the square wave to
the LED. Which later helps the LED to glow and
allow transmission[1].
ii.
Receiver
Figure 4: Visible light communication
III.
Implementation
The basic hardware implementation used in Li-Fi is
AT89C2051 integrated circuit of microcontroller
with L14G2 integrated circuit of phototransistor.
And essential capacitor and regulator to control the
process of microcontroller.
i.
Flow of implementation
Figure 3: Receiver working
On the receiver side exact opposite operation takes
place the light received from the LED is captured
by the phototransistor which acts as a sensor and
passes the output to the comparator which compares
the binary input and similary the original image is
recovered using Matlab software[1].
iii.
Visible Light Communication
Visible light Communication (VLC) is a modern
communication technology which employs visible
light sources (LEDs) . Li- Fi is implemented using
LED’s . If the LED is ON we transmit a digital 1
and if the LED is OFF we transmit a digital 0. The
continuous flickering of LED helps in data
travelling from one terminal to another[7].
Figure 5: Flowchart
ii.
Algorithm
Step 1:
Image/text or video is given as an input to the
sender PC consisting of a matlab program
reserved for image processing of the input
image.
Step 2:
Image processing is done in the sender PC ,the
output of which is processed by the
microcontroller connected to PC via a serial port
using MAX232 .
Step 3:
Depending upon the output of microcontroller
the led's connected to one of its port get toggled
.
Step 4:
At the receiver side photodetection takes place
using phototransistor placed at the receiver end.
Step 5:
Then the microcontroller at the receiver side
conducts the binary conversion of the input data
taken from phototransistor output.
Step 6:
This data is received by the receiver PC
connected to microcontroller via serial port
processed the data in order to reconstruct the
send image at the receiver side by using the
matlab program .
iii.
Block diagram of Li-Fi :
● MICROCONTROLLER: Microcontroller is
low power, high performance 8bit
CMOS
microcomputer with 4kb of EPROM
(electrically programmable read only memory) .
Figure 6: Block Diagram of Li-Fi
● PC (Transmitter & Receiver): It is used to
provide the operation of image processing to
be done at the transmitter side for sending the
input image and at the receiver side for
reconstructing the send image .This processing
is done using Matlab software in PC.
● Phototransistor: It produces some voltage at
its output terminal connected to microcontroller
when lights from led’s fall on it. Phototransistor
is a device that converts light energy into
electric energy. Phototransistors are same as
photo resistors produce both current and
voltage, while photo resistors only produce
current.
● USB to TTL: The cable is easiest way ever
to connect to your microcontroller router
serial solace port.
● Comparator (LM358N) : In electronics, a
comparator is a device that equate two
voltages or currents and outputs a digital
signal indicating larger voltage.
IV.
Experimental setup basically comprises
transmitter setup and receiver setup.
i.
ii.
Experimental Setup
Receiver setup
of
Transmitter setup
Figure 7: Transmitter setup
Sr
no.
1
2
3
4
5
6
7
8
Abbreviation
Component
D1
SW1
C1,C3
C2
C4,C5
X1
RT1
IC1
9
L1
DIODE
SWITCH
CAPACITOR
CAPACITOR
CAPACITOR
CRYSTAL
REGULATOR
20 PINS
SOCKET(89C2051)
LED
10
11
R1
SIL1
12
B1
Figure 8: Receiver setup
Sr
no.
1
2
3
4
5
6
7
8
Abbreviatio
n
D1
SW1
C1,C3
C2
C4,C5
X1
RT1
IC1
9
L2
DIODE
SWITCH
CAPACITOR
CAPACITOR
CAPACITOR
CRYSTAL
REGULATOR
20 PINS
SOCKET(89C2051)
PHOTODETECTOR
RESISTOR
SIL SOCKET
10
11
R1
SIL1
RESISTOR
SIL SOCKET
BUG STRIP
12
B1
BUG STRIP
Table 1 : components of transmitter
Component
Table 2: components of receiver
iii.
Power supply
V.
Results and Discussion
Using light as a data transmission medium helps to
securely transmit data as it overcomes the
disadvantage of data leakage and efficiently
transmit multimedia data over a medium. It uses
Visible light communication technology[3].
Figure 9: Power supply
Connector:
2-pin screw terminal is basically a connector which
is used to interface power supply section with other
circuits through wires .
Bridge Rectifier:
W10 full wave bridge rectifier is used to convert
incoming AC signal into varying DC signal. i.e it
consist of ripple at the output.
Visible light communication using white LEDs
offers the potential for such alternative. The main
reasons are as follows[7]:
• Bandwidth is not limited.
• Existing local power line infrastructure can
potentially be utilized.
• Transmitters and receivers devices are cheap, and
there is no need for expensive RF units.
Filter Capacitor :
Filter capacitor of 2200uf at output of bridge
rectifier is used to provide less ripple at the output
which is suitable for most electronic circuits.
Regulator:
Regulator IC is used to provide constant DC or
smooth output with no ripple.
Sr
no.
Abbreviation
Component
1
BR1
BRIDGE RECTIFIER
2
RT1
REGULATOR
3
C1
CAPACITOR
4
C2
CAPACITOR
5
C3
CAPACITOR
6
CN1
CONNECTOR
7
B1
BUG STRIP
Figure 10: Visible light communication using LOS
Table4: Comparison between communication technologies
Table 3: component table of power supply
VI.
CONCLUSION AND FUTURE
SCOPE
Conclusion from the above implemented concept is
data Transmission using light is cheaper and
secured
We can use Li-Fi in future in which data for smart
phones , tablets etc can be dealt using lights fitted in
the room. Radio waves cannot be used by
commuters in aircrafts. LED-based lights are
already used in aircraft cabins and each of these
lights could be potentials VLC transmitters to
provide both illumination and media services for
travelers. Moreover, this will reduce the aircraft
construction costs and its weight[6].
Underwater ROVs (Remotely Operated Vehicles)
operate from large cables that supply their power
and allow them to receive signals from their pilots
above. They could also use their front lights to
communicate with each other, processing data
independently and sending their information back to
the surface[4] .
VII.
REFRENCES
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“OFDM Visible Light Wireless Communication
Based on White LEDs” in International University
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Infrared
Communications,”
in
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pp. 1182–1186.
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and
Rabadan-J:
‘Lowcost
diffuse
wireless optical communication system based on
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Petersburg, Russia. 28 June 1 July 2006., pp.
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Broadband Access over Medium&Low Voltage
Power-lines and use of White LEDs for Indoor
Communications. In IEEE CCNC 2006 proceedings
[5] Amirshahi, P. and Kavehrad, M. 2006.
Broadband access over medium and low voltage
powerlines and use of white light emitting diodes for
indoor communications. In IEEE Consumer
Communications & Networking Conference, Las
Vegas, Nevada. Citeseer.
[6] J. Carruthers and J. Kahn, “Multiple-Subcarrier
Modulation for Nondirected
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[7] Dobroslav Tsonev, Sinan Sinanovic and Harald
Haas, “Novel Unipolar Orthogonal Frequency
Division Multiplexing (U-OFDM) for Optical
Wireless”, IEEE, 2012