Cooperative multihop connectivity performance in visible light communications

In this work, we have studied the cooperative multi-hop communication using relays to increase the connectivity in visible light communications (VLC). Short transmission range, narrow field of view and occlusion/obstruction by object are limiting the user connectivity to the access point in VLC. The connectivity performance of such cooperative communications is characterized by taking into account optical line-of-sight (LOS) channel model, relay selection algorithm, velocity of user, semi-angle at half power of the light emitting diode (LED) and the field of view (FOV) of the photo detector. Simulations have been performed to evaluate the connectivity performance of such networks with and without relays. In user connectivity performance several simulation parameters are considered: user density, coverage range ratio of multi-hop region (MR), relay probabilities. Simulation results reveal that in case of all considered simulation parameters user connectivity increases using relays in comparison to without relays.