Dissertation: Building a Prototype VLC System for Indoor Stadium

This dissertation presents a comprehensive study on building a prototype Visible Light Communication (VLC) system for an indoor stadium. The research addresses the limitations of radio frequency (RF) communication, such as bandwidth constraints and interference, and proposes VLC as a viable alternative. The dissertation explores the history, need, and advantages of VLC, including its large bandwidth and reduced susceptibility to electromagnetic interference. It delves into the hardware construction, including the MAC and physical layers, channel configuration, and the characteristics of light-emitting diodes (LEDs). The study also covers modulation techniques, such as Orthogonal Frequency Division Multiplexing (OFDM), and their impact on system performance. The practical outcomes demonstrate an effective data rate of 2.5 Gb/s in a free-space communication setup of 5 meters, along with a significant reduction in peak-to-average power ratio. The dissertation also considers the application of VLC in an indoor stadium environment, discussing factors like multiple wavelengths and optical interference. The document concludes with a discussion of the advantages and disadvantages of VLC, along with potential areas for future research and development.

How to build a prototype of working Visible Light
Communication System in an indoor stadium
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Dissertation submitted in partial fulfillment for the degree
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Abstract
Radio Signal interaction is suffering from disturbance and large dormancy problems.
Additionally, Radio signal interaction takes an individual set up for transmitting and
acceptance of those signals. Conquering the prescribed restrictions, Communication through
Visible Light (Visual Light Communication) is a favored approach due to a large bandwidth
and low response to the disturbances coming from electrically magnetic resources. This trend
of the steady state light brings an alternative to florescent lights by Light Emitting Diodes
(Light Emitting Diodes) that furthermore motivates in the utilization of communication
through the light that is visible. The report brings a study of the uses, structures, methods that
modulates, standardizing and find out the difficulties in communication through Visual Light.
There is a technique that is recommended with another type of modulation known as
Orthogonal Frequency Division Multiplexing (OFDM). This is practically proven in the
range of a large-velocity beam of laser light communication set up with cheap LASER beam
of wavelength 450 nm of the blue color. This procedure is utilized in order to decrease a large
peak-to-average power percentage of the Orthogonal Frequency Division Multiplexing wave.
The practical outcomes display an effectively accomplished speed of 2.5 Gb/s below the
communication in the free space of the size 5m and a Peak to Average Power decrease,
approximately of 3.3 dB in a constant function of cumulative distribution in the order of
about 10-3 in comparison with the standard system with no scheme.
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Table of contents
Abstract.......................................................................................................................................i
Table of contents........................................................................................................................ii
Acknowledgement....................................................................................................................iv
Attestation..................................................................................................................................v
1 Introduction........................................................................................................................1
2 Visible Light Communication (VLC)................................................................................2
2.1 History.........................................................................................................................3
3 What is the need?...............................................................................................................5
4 Hardware construction of a VLC system...........................................................................6
4.1 MAC Layer..................................................................................................................6
4.2 Physical Layer.............................................................................................................7
4.3 Channel configuration.................................................................................................8
4.3.1 Comparison with IR...........................................................................................10
4.4 Transmitter................................................................................................................11
4.4.1 Light Emitting Diodes characteristics................................................................13
4.4.2 Brightness control..............................................................................................13
4.5 Receiver.....................................................................................................................16
5 Modelling of for Indoor stadium lighting........................................................................21
5.1 Configuration of VLC link........................................................................................21
5.2 Model of directed LOS channel................................................................................22
5.3 Model of non-directed LOS optical channel.............................................................24
5.4 Signal to Noise ratio..................................................................................................25
6 Visual Light Communication considerations for indoor stadium....................................27
6.1 Multiple wavelengths................................................................................................27
6.2 Optical interference noise..........................................................................................28
6.3 Recent research..........................................................................................................29
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7 Modulation Techniques for Visual Light Communication..............................................30
7.1 Factors that affects the modulation............................................................................30
7.1.1 Dimming............................................................................................................30
7.1.2 Flickering...........................................................................................................30
7.2 Modulation techniques used in the constructed VLC system...................................31
7.2.1 ON-OFF Keying (OOK)....................................................................................31
7.2.2 Pulse Modulation Techniques............................................................................31
7.2.3 Color Shift Keying (CSK)..................................................................................32
8 Advantages.......................................................................................................................34
8.1 Capability..................................................................................................................34
8.2 Effectiveness..............................................................................................................34
8.3 Availability................................................................................................................34
8.4 Protection...................................................................................................................34
9 Disadvantages..................................................................................................................35
10 Conclusion........................................................................................................................36
10.1 Future work............................................................................................................36
References...................................................................................................................................i
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Acknowledgement
I want to acknowledge my teachers, staff and fellow students without whom my work
wouldn’t have finished. Their support was precious. The constant support encouraged me to
see the actual scenario of this area in today’s world.
Apart from them I would like to thank my parents who were always behind me throughout
this project and helped me to research from the sources and last but not the least a special
thanks to the god almighty because he helped me a lot and inspired me to make my way
through the challenges that came before me while designing this project.
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Attestation
The nature of Plagiarism is very well understood by me and also I understand the policy of
my University in this regard. Violation of any copyright is a cyber- crime and I am very much
aware of this.
I certify that this report is my genuine work by me in the University session except that I
gathered some knowledge with the help of certain books which I clearly referenced.
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1 Introduction
The not so abundant band of Radio Frequency puts restrictions over the rising needs for
uninterrupted connection with large capability. As per CISCO, you will see an eleven time
upsurge of the cellular data visitors in 2018 in comparison with the year 2013. This upsurge
of products in getting hold of the cellular systems plays the principal role behind the sudden
upsurge in the cellular traffic. Additionally, with the advent of social services (like Facebook,
linked in and Twitter) boosted the additional data visitors. In addition to the spectrum
insufficiency problems in Radio Frequency wireless communication, disturbances cause
further issues because most of the wireless systems are electrically magnetic in nature. The
Radio Frequency interaction is suffering from issues like (a) Crossing over, relating to
Federal Aviation Administration (FAA) the usage of mobiles upon airplanes triggers
disturbance with the devices that helps in navigation. Additionally, mobiles on plane will also
stimulate the interruption with floor program towers since discussed by Federal Conversation
Commission (FCC). (b) Whatever is the disturbance, it is clear that in a communication that
requires no wire which requires surprisingly low requirements of latency (such as with motor
communication, security networks), usage of radio rate of recurrence cannot be really
appropriate because of its restrictions on the bandwidth. (c) Radio Frequency signals easily
permeate through wall space, they have problems with security problems. (d) Upsurge in
Radio Frequency signals, transmitting power past a threshold level leads in the endangerment
of human’s health (e) Communicating with Radio Frequency signals suffers from electric
power shortage since everyone need an individual set up for Radio Frequency
communication. To combat the disadvantages as mentioned, it truly is vital in the
implementation of a new style in the communication area.
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2 Visible Light Communication (VLC)
Communication using visible spectrum of Light devices uses the band of light visible to
human eyes in order to communicate, occupying the band from 380 nm to 750 nm as
depicted in figure 1. The reduced bandwidth problem in RF communication is usually solved
in Visual Light Communication as a result of option of the large bandwidth. The Visual Light
Communication receiver just gets indicators if indeed they have a home in a similar space to
the transmitting device, which means receiving devices beyond your area from Visible Light
Communication resource that never will be capable in having signals and therefore gets the
security protection conditions that happens in the Radio Frequency systems. Like a normal
source of light could be utilized for lighting as well as communication, consequently, saving
the excess energy needed in Radio Frequency systems. Remembering the mentioned positive
aspects, Visible Light Communication becomes an encouraging competitor due to top
features, large width of band and less energy usage (Khan, 2017), (Dilouie, 2014), (Saadi &
Wuttisittikulkij, 2017).
Figure 1 (Khan, 2017)
Important uses of Visual Light Communication are Light Fidelity, motor to motor interaction,
Robotic machines used in hospitals, for communication under water and data portrayed on
signal planks. The Light Fidelity employs noticeable beam of light intended for interaction to
supply broadband net up to 10G pieces /s. Visual Light Communication can easily be utilized
found in motor connection in street alteration notification, sensing the crash before actual
happening and traffic rules violation in order to caution to prevent incidents. The uses
discussed above need interaction with less dormancy, given by Visual Light Communication
due to its large band width, simpler set up because of the existing existence of automobile
lamps and indicators used in traffics. Visual Light Communication offers usage in places
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delicate to electrically magnetic signals, for example in hospitals and airplanes. Here in fact
the indicators of the radio signals hinder other waves. Light is utilized to provide both
illumination and communication using Visual Light Communication schemes. As an
instance, everyone uses light in a place to supply the quantity recognition to a room also other
building information. Problems which are included in the execution of Visual Light
Communication are (a) Crossing over with all the available sources of light, (b) crossing over
among Visual Light Communication products, and (c) interaction of the Visual Light
Communication with the previous systems like Wireless Fidelity. To manage these
difficulties, a Visual Light Communication’s standardization is essential. MAC layer and
PHY layer are expressed for brief communication spectrum using noticeable light-beam.
Around the transmitting part, light-beam is produced depending upon converters of the
wavelength and Light Emitting Diodes (Chen, et al., 2017), (Chen, et al., 2016), (Khalifeh, et
al., 2018), (Lin, et al., 2015). White-colored light-beam predicated on Light Emitting Diodes
are usually produced in di, tri and tetra chromatic settings. The information around the
transmitting part is light modulated; nevertheless, this modulation has to be achieved in so as
to prevent fluctuation. Likewise, the level of dimming that may be chosen to get the desired
degree of modulation so that lighting backup by Light Emitting Diodes is achieved. The
normal Visual Light Communication recipient includes a great amplification signal, optical
filtration system and optic concentrator (Wang, et al., 2012), (King Abdullah University of
Science and Technology, 2018), (McCormick, 2017), (Ould & Mouhamedou, 2017), (Bazzi,
et al., 2016).
2.1 History
In historic occasions, light-beam was employed so as to communicate with the help of
procedures like smoke and fire indications. Romans utilized shining metal discs intended for
sunshine representation for handling lengthy communication over distance. Lines of
Semaphore centered OC (optical communication). The 1st visible telegraphy system
originated by Claude Chappe in France. Some towers outfitted with semaphores were being
used in order to exchange the information between towns. A wireless photo voltaic telegraph-
system known as Heliograph was produced by United States Armed Service was predicated
on flashes of Morse code with reflection. These whizzes were founded through possible
cross-over from light having a shutter or perhaps momentary reflection attachments. Later
around 1880, a photo phone that was launched by Graham Bell, predicated in sending tone of
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sound transmission over the light. This tone of sound, usually extending towards a reflection
that in turn caused vibration over the reflection. Reflections were reflected by the light,
capturing the vibrations as well. In receiving part this light-beam was gathered and
transformed again to tone of sound transmission. A greatest disadvantage of this system is the
fact it generally doesn’t works very nicely in gloomy conditions. Optic interaction didn't
earned a lot of recognition until the introduction of Mild Amplification simply by Stimulated
Release of Rays (Laser beam). In the 1970s, Corning Integrated effectively constructed
optical fibers in order to use in commercial needs with less damping. The Gallium Arsenide
semiconductor laser beam was the first one to be designed in those days use with optical
dietary fiber cables to get long range communication. In-fiber Bragg grating and optical
fibers amplifier introduction was the foundation in trending in optical communication in
twentieth century (GBI Research, 2011). Visual Light Communication is a kind of
communication in optics, using a number of signals falling under 430-790 THz. 2003
witnessed data transmission using only the Light Emitting Diodes at the Nakagawa
Laboratory in Keio University, Japan (Yuan, et al., 2017), (John, 2018).
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3 What is the need?
Necessity of band for information exchange is raising with a speed of 109% per annum yet
the current developments achieved just 13% development annually. The present systems of
communication will be extremely ineffective like in Radio Frequency systems just a few
energy is usually used for interaction, rest all is definitely wasted. Credited to extremely large
traffic in channel, issue continues in current systems. Radio Frequency can be clinically
demonstrated to become unfit for human beings plus it provides surge many neurological
illnesses and additional complications as well. Right now the query comes Why just Visual
Light Communication? The solution is usually around you that people possess several
quantities of Light Emitting Diodes about us after that why to maintain their particular make
use of restricted to lighting goal. Light Emitting Diodes can provide trend in these systems.
The Light Emitting Diodes offers recently developing within an exponential method. As the
1960s Light Emitting Diodes possessed bending of the resultant light and energy
effectiveness. Light Emitting Diodes will certainly function like a communication goal and
lighting applications and therefore decreases price, raising the performance. New Light
Emitting Diodes arriving inside the marketplace referred to as Resonant Cavity (RC) Light
Emitting Diodes are extremely effective. They will possess extremely shiny mild and low
power usage. In spite of the ideals being positive conjecture of white light-beam Light
Emitting Diodes, real Luxeon Rebel Light Emitting Diodes accomplish ideal 75 luminous/
Watts, with a good life time of 50,000 hours with 70% repair, after powering up with a
current of 699mA. And the advanced Luxeon K2 Light Emitting Diodes is capable of
attaining around two hundred lm/w, and a life time of 50,000 hours with the same repair rate,
once powered with 1A current (Biton & Arnon, 2018), (J, 2018).
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4 Hardware construction of a VLC system
Both the elements of the Visual Light Communication system: the transmitting and receiving
parts generally contain 3 common levels. They will be the physical coating, MAC level and
software layer as shown in figure 2. In IEEE 802.15.7. 1215.7, just two levels (namely
physical and MAC layers) are defined in order to achieve simplicity. Here we will be using
BBB, Beaglebone Black as the platform for developing. It has many advantages. It is cheap
and powerful computer and small as well.
Figure 2 (Khan, 2017)
4.1 MAC Layer
Tasks accomplished simply by MAC (Medium Gain access to Control) consist of the
following supports:
(1) Flexibility (2) Dimming (3) Presence (4) Security (5) Techniques in the minimization of
fluctuations (6) Color function (7) Network beacons era (8) VPAN association and
disassociation (9) Offering trusted hyperlink among peer MAC organizations. The following
are supported by the MAC layer- peer-to-peer, star and broadcast, illustrated in figure 2.
Communication inside the star methodology is conducted using a separate central controller.
All the nodes talk to one another throughout the centralized control. The role from the
coordinator inside the peer-to-peer methodology is conducted simply by one of both involved
nodes with interaction with one another as shown in figure 3.
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