  The increased proliferation of connected devices requires a paradigm shift
towards the development of innovative technologies for the next generation of
wireless systems. One of the key challenges, however, is the spectrum scarcity,
owing to the unprecedented broadband penetration rate in recent years. Visible
light communications (VLC) has recently emerged as a possible solution to
enable high-speed short-range communications. However, VLC systems suffer from
several limitations, including the limited modulation bandwidth of
light-emitting diodes. Consequently, several multiple access techniques (MA),
e.g., space-division multiple access (SDMA) and non-orthogonal multiple access
(NOMA), have been considered for VLC networks. Despite their promising
multiplexing gains, their performance is somewhat limited. In this article, we
first provide an overview of the key MA technologies used in VLC systems. Then,
we introduce rate-splitting multiple access (RSMA), which was initially
proposed for RF systems and discuss its potentials in VLC systems. Through
system modeling and simulations of an RSMA-based two-use scenario, we
illustrate the flexibility of RSMA in generalizing NOMA and SDMA, as well as
its superiority in terms of weighted sum rate (WSR) in VLC. Finally, we discuss
challenges, open issues, and research directions, which will enable the
practical realization of RSMA in VLC.
