Rate Splitting Multiple Access-Aided MISO Visible Light Communications

In this paper, we focus on the optimal beamformer design for rate splitting multiple access (RSMA)-aided multiple-input single-output (MISO) visible light communication (VLC) networks. First, we derive the closed-form lower bounds of the achievable rate of each user, which are the first theoretical bound of achievable rate for RSMA-aided VLC networks. Second, we investigate the optimal beamformer design for RSMA-aided VLC networks to maximize the sum rate under the optical and electrical power constraints. Since this optimal problem is non-convex, a concave-convex procedure (CCCP)-based iterative algorithm is proposed to approximate the non-convex term by the convex lower bound at each iteration. Thus, the optimal beamformer design problem can be solved iteratively until convergence, and a high-quality suboptimal solution can be obtained. In addition, we show that the proposed algorithms of RSMA-aided networks can achieve superior performance compared with space-division multiple access (SDMA) and non-orthogonal multiple access (NOMA).