New Algorithms for Energy-Efficient VLC Networks with User-Centric Cell Formation

The ever-increasing demand in high data rate has pushed the attention of the researchers to utilize the unregulated visible light spectrum for communication. This paper proposes a joint access-point (AP) association and power allocation algorithms for energy-efficiency (EE) maximization in visible light communication networks. Based on the user-centric design, we first show that the cell formation and power allocation are interlinked problems and should be treated jointly. We start by proposing a new algorithm for users' clustering and then associating all the APs to the clustered users based on a proposed metric. We then propose two algorithms that jointly allocate the power, under quality-of-service constraints, and decide which APs must be prevented from participating in communication. The first algorithm is designed to maximize the EE, while the other algorithm is designed to reduce the complexity of the first algorithm with acceptable degradation in the EE. Different from the related literature that allocated the power with the worst case interference information, we propose an iterative algorithm that allocates the power based on exact interference information, which significantly improves the EE. The numerical results demonstrate that the proposed algorithms significantly improve the EE compared to the existing work.