  Visible light communication (VLC) builds upon the dual use of existing
lighting infrastructure for wireless data transmission. VLC has recently gained
interest as cost-effective, secure, and energy-efficient wireless access
technology particularly for indoor user-dense environments. While initial
studies in this area are mainly limited to single-user point-to-point links,
more recent efforts have focused on multi-user VLC systems in an effort to
transform VLC into a scalable and fully networked wireless technology. In this
paper, we provide a comprehensive overview of multi-user VLC systems discussing
the recent advances on multi-user precoding, multiple access, resource
allocation, and mobility management. We further provide possible directions of
future research in this emerging topic.
