Abstract
Power line communications (PLC) and visible light communications (VLC) are two emerging
telecommunication technologies which may be seriously considered in the near future.
This is due to the fact that both technologies present a channel or antennas, normally
used for other purposes. The power wires which constitute the PLC channel are primarily
exploited for electrical energy transmission, and the light bulbs which are VLC transmitting
antennas are sources of illumination. PLC and VLC technologies also present four
meaningful similarities: (i) Impulsive noise is the most destructive PLC noise, it is modelled
using Poisson distribution. Similarly, the VLC channel is dominated by shot noise,
also modelled using the same statistical distribution. (ii) Multiple reflections of the transmitted
signal characterise the PLC channel. This is similar to the multipath propagation
of VLC, which is due to multiple reflections that light rays undergo in the transmission
environment. (iii) PLC technology presents economic advantages owing to the fact that it
uses ubiquitous power wires already installed. This is the case of VLC technology, which
uses the omnipresent light bulbs, naturally used for illumination. (iv) Both power wires
and light bulbs are physically connected; light bulbs are powered through power wires.
These similarities, added to the fact that both PLC and VLC are naturally connected to
each other (light sources receive electrical energy from the electrical cable), are advantages
related to cost effectiveness which is of a great importance in engineering. Among
the applications of these two communication technologies, some are low data rate based.
Generally, these low data rate applications require a modulation technique different from
those exploited in high data applications. Lots of low data rate modulation schemes are
used in communication engineering, they include on-off keying (OOK), pulse position
modulation (PPM) and its variances, and frequency shift keying (FSK), to mention only...
M.Ing. (Electrical Engineering)