  In this letter, we propose a non-orthogonal multiple access (NOMA) based
scheme for multi-cell indoor visible light communications (VLC), where
cell-edge user is jointly served by multiple cells. Unlike the typical designs
in the existing literature, the proposed scheme doesn't involve complex domain
and direct current bias addition, which makes the design simple and feasible
for real time implementation in indoor VLC. The symbol error rate (SER) of the
proposed NOMA scheme is analysed using analytical and simulation results, and
is compared with orthogonal multiple access (OMA). It is observed that the
average SER of the users with the proposed NOMA is marginally degraded as
compared to OMA. However, the SER of cell-edge user with the proposed NOMA is
significantly improved with joint maximum likelihood decoding, and outperforms
successive interference cancellation based decoding and OMA, with trade-off on
computational complexity.
