Robust Max-Min Fair Beamforming Design for Rate Splitting Multiple Access-aided Visible Light Communications

TL;DR

Numerical results show that the proposed robust beamforming design algorithm for RSMA-aided VLC network achieves a superior performance over the existing ones for space-division multiple access (SDMA) and nonorthogonal multiple access (NOMA).

Abstract

This paper addresses the robust beamforming design for rate splitting multiple access (RSMA)-aided visible light communication (VLC) networks with imperfect channel state information at the transmitter (CSIT). In particular, we first derive the theoretical lower bound for the channel capacity of RSMA-aided VLC networks. Then we investigate the beamforming design to solve the max-min fairness (MMF) problem of RSMA-aided VLC networks under the practical optical power constraint and electrical power constraint while considering the practical imperfect CSIT scenario. To address the problem, we propose a constrained-concave-convex programming (CCCP)-based beamforming design algorithm which exploits semidefinite relaxation (SDR) technique and a penalty method to deal with the rank-one constraint caused by SDR. Numerical results show that the proposed robust beamforming design algorithm for RSMA-aided VLC network achieves a superior performance over the existing ones for space-division multiple access (SDMA) and non-orthogonal multiple access (NOMA).

Figures (12)

• Figure 1: The considered downlink RSMA-aided multi-user MISO VLC network.
• Figure 2: The geometry of mobile users.
• Figure 3: Proposed optimization framework to solve $\mathcal{P}_0$.
• Figure 4: Room configuration with LEDs’ locations.
• Figure 5: Convergence analysis of the proposed algorithm.