Joint Resource Allocation for IRS-Aided VLC Network with Energy Harvesting

To satisfy the explosive growing traffic demands for high-speed service, visible light communication (VLC) has become a promising technology these years. This paper presents a novel intelligent reflective surface (IRS)-aided VLC network system, which takes into account the existence of both information users (IUs) for receiving data information and energy harvesting users (EHUs) for capturing light energy. We determine the IRS association, power allocation, as well as direct current (DC) offset distribution to maximize the sum rate at the IUs, subject to the energy constraints at EHUs. As a solution to such a complex non-convex optimization problem, we propose a two-stage alternating optimization algorithm by decomposing it into two subproblems, with each subproblem being solved iteratively. We solve the subproblem of IRS association with a heuristic method and tackle another subproblem of power allocation and DC offset distribution with a successive convex approximation (SCA)-based algorithm. Based on our numerical results, we conclude that the proposed algorithm is convergent, and a significant improvement in sum rate can be achieved by joint resource management while meeting certain requirement of harvesting energy. Moreover, IRS can reduce the sensitivity to obstacles and improve sum rate performance in VLC.