Proactive Resource Allocation for Aggregated VLC/RF Networks With Outdated CSI

In this letter, the case of an aggregated VLC/RF network is presented, where the users can be served simultaneously by both a visible light communication (VLC) carrier and a radio-frequency (RF) carrier to increase their achievable data rate. The optimal resource allocation in the network is dependent on always having accurate channel state information (CSI), otherwise, in the case of outdated CSI, the system is prone to sub-optimally allocating resources and, due to the limited coverage of VLC, users may also experience outage. A closed-form expression for the coverage probability is presented for a user moving randomly in the cell. Using this, a proactive resource allocation algorithm is proposed that takes into account outdated CSI which can occur due to user movement, and ensures the outage probability is low in the network without diminishing the average achievable data rate of users. Finally, simulation results validate the proposed analysis and showcase the effectiveness of this approach.