Coordinated Transmission Based Interference Mitigation in VLC Network

Nowadays, multiple access points and subcarrier transmission are widely used in visible light communication(VLC) to achieve seamless coverage and high spectral efficiency. However, the reuse of subcarriers may cause severe interference for users located in overlapping areas using co-channel. Those existing methods utilize interference managements to solve this issue, but at the cost of bandwidth inefficiency. Hence, a designated resource allocation that includes interference mitigation is needed without degrading the performance of the network. In this paper, a graph theory based resource allocation algorithm in the downlink is proposed, which not only mitigates the interference, but also improves the capacity and fairness of the system. Numeric results demonstrate that the proposed scheme exhibits a 133.6% and a 25.0% average system throughput improvement compared to the Round Robin scheme and proportional fairness scheme. Additionally, a better performance in fairness is obtained by the proposed scheme.