Optimized joint LiFi coordinated multipoint joint transmission clustering and load balancing for hybrid LiFi and WiFi networks

Abstract

Hybrid light fidelity (LiFi) and wireless fidelity (WiFi) networks provide a promising solution for future indoor wireless communication. Hybrid networks face the challenge of imbalanced cell load due to the uneven distribution of user equipment (UE), and they need to suppress inter-cell interference induced by the dense deployment of LiFi access points (APs). In this paper, with the aim to efficiently establish UE-AP associations and allocate resources, we propose a potential game (PG) aided design of joint user-centric LiFi coordinated multipoint (CoMP) joint transmission (JT) clustering and load balancing (LB). In our design, we formulate the joint design problem as a mixed-integer nonlinear programming (MINLP) problem, which integrates the requirement for the minimum data rate of each UE. With the aim to maximize the system throughput under proportional fairness constraints, we propose to build a PG model to solve the MINLP problem. Then we derive the Nash equilibrium based on the best-response dynamics, and thus a suboptimal solution is attained. Thanks to the space diversity gain brought by our joint LiFi CoMP-JT clustering and LB design, the signal-to-interference-plus-noise ratio can be improved. Thus, when the physical layer configurations remain the same, hybrid networks can achieve larger capacity and better reliability performances. Simulation results validate that hybrid networks using our presented design would achieve better throughput and satisfaction performances than benchmarks.