Research On Performance Analysis And Optimization Of Hybrid Cooperative Visible Light Communication/Radio Frequency Communication System For Internet Of Things

With the growing adoption of the Internet of Things(Io T),billions of massive communication connections,explosive growth of mobile data traffic,and mushrooming applications and services have caused problems such as spectrum scarcity,limited coverage,and energy constraint encountered,which poses a tough challenge to the sustainable development of future networks.Focusing on the new spectrum,wide coverage,and long endurance encountered in the application of Io T,an efficient and robust hybrid visible light communication(VLC)/radio frequency(RF)cooperative relay(CR)system based on simultaneous lightwave information and power transfer(SLIPT)is proposed by the fusion of traditional RF and new VLC.To bridge the light emitting diode source and the destination far away,an off-the-grid relay is employed that moves randomly within source coverage,thus dividing the signal transmission into two hops.Specifically,the optical signal received at the relay is separated into alternating current and direct current components for information decoding and energy harvesting,respectively in the 1st hop.Then the energy harvested is used to forward the decoded source information to the destination by using RF in the 2nd hop.Subject to constraints imposed on both the average and the peak powers of source,the performances of the two hops are respectively analyzed by considering the distinct channel conditions across the VLC channel and RF channel and the signal processing at the intermediate relay.On this basis,the end-to-end outage probability,throughput,and energy efficiency of the system are analytically derived in closed-form expressions,which are applicable for efficient evaluation of the system performance as well as characterizing the impact of key parameters.In addition,the minimization of the end-to-end outage probability is formulated as an optimization problem.This problem is then solved with a joint design of the peak amplitude and the direct current bias of the source transmitter,by trading-off between the performances of two successive hops.Simulation results demonstrate that with proper parameter configurations,the bottlenecks in the Io T,such as less spectrum,small coverage,and short endurance,can be effectively alleviated by the proposed system.On the other hand,through the performance comparison between the optimal scheme and the benchmark scheme,the information flow and the energy flow can be dynamically balanced by the proposed optimal solution,resulting in significant performance gains in terms of outage probability and throughput.Therefore,the above verifies the feasibility of the proposed system and the efficiency of the proposed optimal solution.