  Reliable data transmissions and offering better mobility to the end user can
be achieved by integrating different communication systems. In this paper, we
investigate the performance of a cascaded indoor power line communication
(PLC)/visible light communication (VLC) system with the presence of an
amplify-and-forward (AF) relay. Using the pre-installed infrastructure of
electricity wiring networks gives the advantage to use PLC as a backbone for
VLCs. The performance of the proposed hybrid system is discussed in terms of
the average capacity. A mathematical method is developed for this network to
formulate the capacity by exploiting the statistical properties of both the PLC
and VLC channels. The derived analytical expressions are validated by Monte
Carlo simulations. The results showed that there is a considerable improvement
in the performance of the hybrid system as the relay gain increases whereas it
deteriorates with increasing the end-to-end distance. A comparison between the
performance of a parallel hybrid/PLC and hybrid systems is also provided. It is
found that the hybrid/PLC system outperforms the hybrid one. However, the user
mobility offered by the latter system remains the main advantage over the
former approach.
