  Optical wireless communication (OWC) has the potential to provide high
communication speeds that support the massive use of the Internet that is
expected in the near future. In OWC, optical access points (APs) are deployed
on the celling to serve multiple users. In this context, efficient multiple
access schemes are required to share the resources among the users and align
multi-user interference. Recently, non-orthogonal multiple access (NOMA) has
been studied to serve multiple users simultaneously using the same resources,
while a different power level is allocated to each user. Despite the acceptable
performance of NOMA, users might experience a high packet loss due to high
noise, which results from the use of successive interference cancelation (SIC).
In this work, random linear network coding (RLNC) is proposed to enhance the
performance of NOMA in an optical wireless network where users are divided into
multicast groups, and each group contains users that slightly differ in their
channel gains. Moreover, a fixed power allocation (FPA) strategy is considered
among these groups to avoid complexity. The performance of the proposed scheme
is evaluated in terms of total packet success probability. The results show
that the proposed scheme is more suitable for the network considered compared
to other benchmark schemes such as traditional NOMA and orthogonal transmission
schemes. Moreover, the total packet success probability is highly affected by
the level of power allocated to each group in all the scenarios.
