  Resource allocation and interference management are two main issues that need
to be carefully addressed in visible light communication (VLC) systems. In this
paper, we propose a resource allocation scheme that can also handle the
inter-cell interference in a multi-user VLC system that employs orthogonal
frequency division multiple access (OFDMA). Particularly, we suggest dividing
the cell coverage into two non-overlapping zones and performing a two-step
resource allocation process, in which each step corresponds to a different
level of allocating resources, i.e., zone and user levels. We initially define
both zones in terms of the physical area and the amount of allocated resources
and we investigate the impact of illumination requirements on defining both
zones. Through simulations, we evaluate the performance of the proposed scheme
in terms of the area spectral efficiency and the fairness level between the two
zones. We show that both performance measures can be potentially enhanced by
carefully setting a certain design parameter that reflects the priority level
of the users located in the region around the cell center, denoted as Zone 0,
in terms of the achievable rate. We further eventuate the system performance in
a realistic transmission scenario using a simulation tool.
