Research On V2V Routing Protocol Based On Visible Light Communication

In recent years,with the increase of vehicle ownership,urban traffic safety has become a hot research direction.As a key technology of intelligent transportation,Internet of Vehicles has been used to solve traffic problems and realize information exchange between vehicle to vehicle(V2V)communication.In V2 V communication,the vehicle density is very high.The traditional vehicle networking is based on the radio communication mode.Due to the limited spectrum range,there is a shortage of channel resources.Visible Light Communication(VLC)has the advantages of low delay and wide band with Visible Light spectrum between 400～790THz.It has great research value to apply VLC to Internet of Vehicles.The V2 V routing protocol based on VLC provides the optimal route selection scheme from the source vehicle to the destination vehicle,and ensures the reliable performance of the communication between vehicles.The proposed routing protocol research can also overcome the limitations of V2 V routing protocol based on radio frequency communication,such as long delay and vulnerability to attack,and solve the problem of long-distance multi-scene communication.The research contents of this paper are as follows:Firstly,the characteristics of visible light communication and the classical model of visible light gain are introduced.In the straight road scenario,the vehicle speed prediction based on the input-output hidden Markov model is studied,and the predicted speed is introduced into the visible light gain to get the improved visible light gain model.In the curve scene,the turning trajectory model is studied,and the modified models of the the incidence and irradiance angles of the VLC transmission are established,so as to obtain the improved visible light gain model based on the trajectory model.The models in the two scenarios provided a foundation for the subsequent research on routing protocols.Then,based on the visible light gain model of speed prediction,the vehicle candidate set scheme was studied by using the received optical power and the number of communicable vehicles,and the routing function was established.On the basis of the study a V2 V VLC routing algorithm based on multiple hops relay.Each link is judged,and the optimal link is determined on the premise of ensuring the stability of the link and high receiving power.Simulation results show that the proposed routing protocol is superior to the proposed shortest path dynamic routing protocol and tree routing protocol in terms of signal-to-noise ratio and bit error rate.Finally,based on the visible light gain model of curved scene,the VLC loss model is established,and the delay model of VLC is introduced.Then,Dedicated Short Range Communication(DSRC)was used as a supplementary technology to establish the optimization index of communication path from the two performance aspects of loss and delay,and a hybrid multi-hop heterogeneous routing optimization model of VLCDSRC was established,which solved the problem that a single VLC would have a great change in the incidence and irradiance angles on the curve,resulting in poor performance.The simulation results show that heterogeneous VLC-DSRC contains the advantages of both VLC and DSRC when considering the routing protocol parameters of delay and loss performance comprehensively,and the heterogeneous VLC-DSRC mode has the best performance especially in the aspect of delay.