Lifi (presentation)

Design, Implementation and Analysis of Li-Fi System in Noisy Environment

MS Electrical Engineering Thesis DefenseMonday, July 13, 2015

Muhammad Aman12SP-MS-EE-003

Dr. Jameel AhmedThesis Supervisor

Department of Electrical EngineeringHITEC University , Taxila Cantt Pakistan

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Sequence Of Presentation

Introduction Background Literature Survey Proposed Model Results

Noise Analysis Model

Lambert Cosine Law

Conclusion Future work References Question/Answers

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Introduction Li-Fi The word Li-Fi (Light Fidelity) in simple words faithfulness of light to

us. It works on VLC (Visible Light Communication)

This idea is given by Dr Harald Hass in October 2011 on the TED forum

He also some time called it the D-light (Digital )

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Background

The history of light fidelity (Li-Fi) begins with the advent of photophone, by Alexander Grahambell in 1880

Dr Harald Hass of Germany, professor of mobile communication at University of Edinburg discovered (Li-Fi) in between Oct 2010 to Oct 2012

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We have about 1.4 millions of radio base stations all over the world

[1] A View Of The Base Station

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Continued…

More than 5 billion of mobile hand sets for the purpose of Communication

[2] Gadgets Of Communication 6

Continued…

With these mobile phone we transmit more than (600 tera bites) of data every month

Therefore wireless communication has become a

utility for us like water and electricity in our daily life

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Continued…..

Shortcoming in Wireless Communication

Capacity Fuel Efficiency Availability Security

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Capacity

The way we transmit wireless data is electromagnetically, specifically radio waves, and radio waves are limited, they are expensive and we only have a certain range of it

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Resource Efficiency

1.4 million of cellular masks or radio base stations consume a lot of energy, most of that energy is not used to transmit the wireless data but to keep it cool. The efficiency of such a base station is only 5%

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Availability

We have to switch off our mobile phones during flights, in hospitals, and many other places due to security issues

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Security

The radio waves can penetrate through walls and can be intercepted with sophisticated equipment which is a big constraint in present wireless communication

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Electromagnetic spectrum

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Sources of Visible Light

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Incandescent Bulb Halogen Incandescent Bulb Compact Florescent Bulb Light Emitting Diode

Benefits of LED

Capable Of Emitting More Lumens Small Size Any Colored Light Can Be Produced Heat Emission Long Working Life Quick Response To Sudden Changes In Voltages

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A single stream of bits moving toward the television with a very low data rate of about 1000 bit/s

Which is not enough for the HD video streaming 16

MotivationMotivation

Two questions arises if this technology is deployed

1. What if we are using it in day light ?

2. Do we have to keep the light on all the time ?

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What if we are using it in day light ?

The receiver only concerns with the on/off states of the light from the transmitter, it have no concern with any continuous light

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Do we have to keep the light on all the time ?

Yes we have to on the light all the time in order to communicate but we can dim it down to a level where it appears to be off and will still be able to communicate

The PWM (Pulse Width Modulation) dimming sequence can be used for the purpose

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How Li-Fi over comes the issues?

Capacity

As this technology uses light for communication purpose, and light sources are present everywhere in our locality, so by using these light sources Li-Fi will over come the capacity constraint

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Efficiency

We are already using LED to get light in our locality, by using these light sources we can overcome the efficiency constraint

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Availability

As we know light is present everywhere, by using those light sources for communication, Li-Fi will overcome the availability constraint

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Security

Light does not penetrate through walls, by this property of light this technology provides an automatic security to our communication in a network

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Potential Applications

Under water exploration robots can use this technology

[3] [4]

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Petro Chemical Plant Environment

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We cannot use radio frequencies because it can easily generate a spark which can create big disaster [6]

In hospital for communication

[8]26

In traffic light and cars now a days have LED based lights that can be used a potential source for communication

[9] 27

Every street bulb can be a potential source for wireless communication and can be access point for internet

[10]28

In airplanes it can be used for wireless communications

[11] 29

Literature Survey Serial No Authors Title Published In Publishing Year

[1] Dr Harald Has High-speed Wireless Networking Using Visible Light

Spie International Society For Optics And Photonics Journal [5]

April,2013

[2] M.V.Bhalerao, S.S.Sonavane, V.kumar

A Survey Of Wireless Communication Using Visible Light

International Journal Of Advances In Engineering & Technology [7]

Jan,2013

[3] M.Thanigaval Li-fi Technology In Wireless Communication

International Journal Of Engineering Research & Technology [16]

October,2013

[4] Hang Elgala, Raed Mashlay And Harald Hass

Indoor Broadcast Via White LED And OFDM

IEEE Transactions On Consumer Electronics [18]

August 2009

[5] N.Navyatha, T.M.Prathyusha, V.Raja, M.Mounika

Li-fi (Light Fidelity)-led Based Alternative

International Journal Of Scientific & Engineering Research[26]

May-2013

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Proposed Model

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Analog Signal

Frequency Modulation A/D LED Drive

Circuitry LED

Clutch

PhotodiodeReceiver Circuitry

D/AFrequency Demodulation

Analog Signal

Proposed Model Animation

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Simulation Model for Transmitter

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Simulation Model for Receiver

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Results

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Simulated Model Noisy Environment

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Results and Analysis

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Results discussion

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Lambert Cosine Law

L=ø/4π

Io=L/r2

Io/=Lcosθ/r2

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Results Case#1Distance = VariableLine Of Sight = Constant

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Case#2Distance = VariableLine Of Sight = Variable

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Case#3Distance = ConstantLine Of Sight = Variable

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Comparative analysis results

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Data1 = Case#1Data2 = Case#2Data3 = Case#3

Conclusion Successful implementation of simulink model for Li-Fi data

transfer After analysis of Li-Fi in noisy environment its is concluded

that if the transmitted signal is distorted by 30% its can be easily retrieved, but if distortion goes up to 50% complex filtering techniques are required to reconstruct the original signal

After implementation lambert cosine law it is concluded that maximum angle of reception is 15 degree from line of sight

Lambert cosine law suggest that max distance for Li-Fi is 9m with single LED

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Future work

Extensive research and development is required for hardware implementation

Work on duplex and full duplex communication can be done Its implementation in PLC (Power Line Communication) is

suggested for future

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References [1] http://www.chronicexposure.org/images/BaseStationXSmall.jpg

[2] http://images.amazon.com/images/G/01/wireless/detail-page/nokia-n8-quintcolors-sm.jpg

[3]http://www.unis.no/60_NEWS/6060_Archive_2010/n_10_03_25_new_technology/NORUS-jan2010-GJ-406_525px.jpg

[4] http://www.sciencebuddies.org/Files/4312/5/Robotics_img013.jpg

[5] Dr Harald has, High-speed wireless networking using visible light, spie international society for optics and photonics, 19 April 2013

[6] http://dilectusrecruitmentsolutions.co.uk/wp-content/uploads/2012/10/refinery.jpg

[7] M.V.Bhalerao, S.S.Sonavane, V.kumar, A Survey Of Wireless Communication Using Visible Light, International Journal Of Advances In Engineering & Technology, Jan. 2013. ©Ijaet, Vol. 5, Issue 2, Pp. 188-197

[8] http://www.jamhosp.com/serendipity/uploads/Pix/led3.jpg

[9] http://pictures.topspeed.com/IMG/crop/200707/led-traffic-lights-c_600x0w.jpg

[10] http://relteuk.com/wp-content/uploads/2015/02/StreetLight-Example.jpg

[11] https://talgroupinc.files.wordpress.com/2013/10/inside-airplane.jpg

[16] M.Thanigaval, Li-Fi Technology in Wireless Communication, International Journal of Engineering Research & Technology (IJERT) Vol. 2 Issue 10, October – 2013.

[18] Hang Elgala, Raed Mashlay and Harald Hass, indoor broadcast via white LED and OFDM, IEEE Transactions on Consumer Electronics, Vol. 55, No. 3, AUGUST 2009

[26] N.Navyatha, T.M.Prathyusha, V.Raja, M.Mounika , Li-Fi (Light fidelity)-LED Based Alternative International Journal of Scientific & Engineering Research, Volume 4, Issue 5, May-2013

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Question Answers

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