Multi-User Grouping for NOMA Enabled VLC System

Driven by the rapid growth of wireless devices and their need for innovative technologies to facilitate a Gigabit-per-second (Gbps) connectivity, visible light communication (VLC) has arisen as a candidate solution. However, the rapid growth of wireless devices necessitates the use of multiple access (MA) techniques to support multi-user Gbps connectivity. In this work, we consider non-orthogonal multiple access (NOMA) as a candidate MA technique for the downlink VLC systems and focus on grouping multiple users so that they can share the same resources. For the same, we propose two multi-user grouping schemes, which exploit the principles of power domain NOMA by maximizing the channel gain differences across the users in a group. The analytical and empirical results corroborate that the proposed schemes can be utilized to group multiple users and improve the overall achievable sum rate.