Résumé:
Visible Light Communication (or VLC) is an emerging area of research in wireless
communication. The technology operates similarly to communication systems that rely on
optical fibers. However, the VLC system utilizes free space as its communication medium. The
advancement of LED (or Light-Emitting Diode) technology has significantly improved
contemporary communication systems. When VLC is used, the LED serves as a transmitter,
and when the receiver is within the direct line of sight, it transmits data in the form of light
signals. The VLC system employs fast light modulation to transfer data, rendering it
challenging for human vision to discern. The detector rapidly interprets the data transmitted by
the LED upon receiving it. The VLC system possesses several significant benefits in
comparison to alternative communication techniques. It is relatively easy to build using an
LED, phototransistor, or photodiode. The VLC system is cost-effective, portable, affordable,
compact, and energy-efficient, mitigates radio interference, and eliminates the need for
underground cables and broadcast licenses. This study examines the design and performance
evaluation of an indoor optical communication system that utilizes visible-light technology.
The simulation software Optisystem is employed for this purpose. Nevertheless, we simulated
the Li-Fi (or Light-Fidelity) system within a room using propagation models, including Lineof-Sight (or LoS) and Non-Line-of-Sight (or NLoS). Furthermore, the suggested model has
been evaluated utilizing the LoS propagation model, employing a single direct route and a
single LED as the transmitter. Conversely, the NLoS propagation model has been analyzed in
several situations, considering a single LED as the transmitter. To validate our concept, we have
examined the effects of the following factors on the proposed system: the variation in the Field
of View (or FOV) at the recipient's end, the variation in the Transmit Half Angle (or THA)
value at the transmitter end, the variation in the bit rate of a Li-Fi link, and the impact of
different ambient noise sources on a Li-Fi link. The simulation findings demonstrate that the
proposed system obtained a bit rate ranging from 10 Mbps to 30 Mbps at an acceptable BER of
1e-6, as simulated in this study. This was observed when the FOV and THA varied from 11.25°
to 90°. The impact of noise intensity on the proposed Li-Fi system was also considered.
