Abstract
In this work, we have initiated to study some standardized modulation schemes for On
Off Keying, Frequency Shift Keying, Pulse Position Modulation, Variable Pulse Position
Modulation (OOK, FSK, PPM, VPPM) and multiple input multiple output (MIMO)
techniques for visible light communication. This study is based on the comparison of the
power of noise occurred in the received signal based on matlab simulation. We started
our study in chapter one by providing the context of the advent of visible light communication
system technology on the market. This enabled us to revisit the phenomenon
of communication back in the former centuries up to nowadays. In fact communication
consists of the exchange of information imposed by the life in communities in different
sector of activities ( Household, families, companies, public transport, military sector,
associative groups, industries ). In addition to these, we highlighted different means of
communication which were used by different stakeholders to exchange information over
the time. In that purpose, we started by traditional means used for the exchange of
information which was followed by the introduction of technology based on the use of
different electromagnetism radiation especially the radio wave. Actually, the adoption
in industry and the usage of a light emitting diode (LED) enables a transition to a new
wireless system technology known as visible light communication. This happened and
was motivated in the context of limited bandwidth in radio frequency based wireless
communication insufficient to cover the need of population in terms of data rate, energy
efficiency which substantially fueled the research of new wireless communication system
technology based on LED use as an alternative to radio frequency based wireless communication
technology. This revolution in the solid state lighting industry come with a
new device (LED) with a great potential in lighting and in communication capable to
replace traditional incandescent, fluorescent and halogen lamps and offers a possibility of higher bandwidths (380 nm and 750 nm) which could be used for higher wireless communication
technology (multigigabits per seconds). This new wireless communication
technology known as visible light communication (VLC) system technology is based on
the exploitation of different functionalities of LED simultaneously used in lighting as in
communication. In our chapter two, we provided a literature review in communication
system technology in general and in LED usage in particular. In the same chapter, we
also provided some references about what was done in terms of standardization by the
Institute of Electronic and Electrical Engineering (IEEE) and other stakeholders in the
matter. Moreover, we undertook a literature review about some challenges ( noise, mobility,
communication range, data rate, system positioning ) imposed by LED usage in its
different applications ( indoors and outdoors ) which should be addressed in order to allow
the exploration of the full potential of the technology. In chapter 3 we present the protocol
of VLC, a basic diagram of a skeleton of transmission program made by the trilogy of
the transmitter, the channel and the receiver. We highlighted the main component used
in each block module, its role, its performance, its limitation. In chapter 4 we present
the modulation technique for VLC, multiple input multiple output (MIMO) techniques,
some standardized modulation schemes for VLC such as OOK, FSK, PPM, VPPM and
their different applications. Alternatively, we also provide the mathematical model of
the VLC system. Therefore, some comparisons between these standardized modulation
schemes based on matlab simulations of BER vs SNR to see which modulation scheme is
more appropriated or is the best based on the obtained results were made. Moreover, we
present some mathematical analysis for VLC. In chapter 5, we presented the results from
modulation analysis described previously followed by the conclusion of our study based
on the obtained results.