Performance Analysis Of Reconfigurable Intelligence Surface-assisted Vehicular Networks

With the development of intelligent transportation and Internet of Vehicles,the demand for automatic driving,real-time positioning and In-Vehicle Infotainment is increasing,and the effectiveness and reliability of data transmission in Internet of Vehicles have become more and more important.However,in the actual scenarios,the transmission signal is obstructed by buildings and interfered by other vehicles.The quality of the signals received and transmitted by the target vehicle is greatly reduced,and the normal communication of the vehicle may be affected by the blocking of the direct link.In order to solve the above problems,this paper introduces Reconfigurable Intelligent Surface(RIS)into the Internet of Vehicles(Io V)system to assist vehicle communication.We analyze the outage probability and ergodic achievable rate of the system,and derive the corresponding analytical expressions.The correctness of the derived theory is verified through simulation.The specific work is as follows:(1)Considering a non-interference RIS-assisted Io V scenario,we derive the analytical expressions of outage probability,ergodic achievable rate and average symbol error probability in this system.Also,the influence of the reflection amplitude on the ergodic achievable rate is explored.We assume that the direct link in the system is completely blocked and the RIS channel obeys Weibull fading.Firstly,the signal-to-noise ratio in this scenario is written.The upper and lower bounds of outage probability and ergodic achievable rate,and average symbol error probability are derived respectively through the central limit theorem,Jensen inequality,and the definition of symbol error probability.Then,based on the analytical solution of the ergodic reachable rate,we derive the upper and lower bounds of the ergodic reachable rate under amplitude conditions that depend on the phase changes,and compare it with the ideal amplitude and random phase.The simulation results compare the theoretical analysis results with the Monte Carlo results,which verify the correctness of the theoretical results obtained in this paper,and fully demonstrate the performance gain brought by the introduction of RIS.(2)Considering the interference scenario of RIS-assisted Io V system,we study the system performance such as interrupt probability and ergodic reachability rate,and analyze the energy efficiency gain which is brought by the introduction of RIS.Also,due to the mutual interference between vehicles,the channel utilizes Nakagami-m fading,Weibull fading and Rayleigh fading respectively.In our work,we derive the analytical expressions of outage probability and ergodic achievable rate.After providing the upper and lower tight bounds for the ergodic achievable rate and high signal-to-noise ratio ergodic achievable rate when the hardware reflection ability loss over time,we compare the energy efficiency between the RIS-assisted Io V system and the traditional Io V system.The simulation results verify that the theoretical bound is close to the Monte Carlo bound,and the performance of RIS-assisted Io V system with optimal phase is better than that of random phase and traditional Io V system.