Power Optimization in MIMO-NOMA VLC Systems Using Fractional and Dynamic Frequency Reuse

This paper investigates power allocation strategies for enhancing the achievable sum rate in indoor Multi-User Visible Light Communication (MUVLC) systems using Multiple-Input Multiple-Output Non-Orthogonal Multiple Access (MIMO-NOMA). Two frequency reuse methods—Fractional Frequency Reuse (FFR) and Dynamic Frequency Reuse (DFR)—are proposed and evaluated against the existing Normalized Gain Difference Power Allocation (NGDPA) technique. Simulation results for a (2×2) MIMO-NOMA-VLC system show that while FFR can offer substantial performance improvements under favorable conditions, its effectiveness diminishes and may even underperform in specific scenarios. In contrast, DFR consistently outperforms NGDPA across a range of network conditions, demonstrating robust and reliable sum rate enhancement. This consistent adaptability makes DFR a more effective and preferred solution for optimizing power allocation and maximizing spectral efficiency in indoor VLC environments.