On Improving the Fairness of NOMA-Based Indoor Visible Light Communication System

In this paper, we improve the fairness of non-orthogonal multiple access (NOMA) by proposing a power allocation scheme that ensures all users experience the same bit error rate (BER) irrespective of their channel conditions. We also derive analytical expressions for the BER obtained using this novel power allocation scheme by applying it to a downlink NOMA-based visible light communication (VLC) system. The numerically simulated results for different scenarios match the analytical results, thereby validating the derived power allocation expression. Finally, we demonstrate a significant improvement in the fairness of NOMA for our novel power allocation scheme compared to the existing gain ratio power allocation and normalized gain difference power allocation schemes.