The Research On Radio Source Management Based On PPPP For Cellular Vehicle-to-Everything

In C-V2X,each V2X message on the PC5 link is configured by the application layer with an independent PPPP(Pro Se Per-Packet Priority)to the access layer.Radio resource management that does not consider PPPP may cause high-priority messages to not be transmitted in a timely manner,thereby endangering road safety.At the same time,resource reuse among users will cause complex co-channel interference problems and degrade system performance.Therefore,the design of radio resource management algorithms that consider PPPP is very necessary.This paper proposes different radio resource management algorithms for different resource scheduling modes under C-V2X.The main contents are as follows:In the centralized resource scheduling mode,in order to guarantee the Qo S of high PPPP priority users and improve the spectrum efficiency,a new radio resource management algorithm is proposed.This algorithm maximizes the information value of the entire system while ensuring the communication reliability of V2X users and the rate of traditional cellular users.First,by introducing the concept of sub-users,the target problem is decomposed into two sub-problems: a power control problem that maximizes the information value in a single RB and a frequency resource selection problem that maximizes the information value of all users.Then,based on the results of power control,a heuristic algorithm is proposed to solve the problem of frequency resource selection.Finally,the power is redistributed according to the result of frequency allocation to obtain the final transmit power.Simulation results show that the proposed algorithm can not only significantly improve the information value of the entire system,but also ensure system reliability.In the distributed resource scheduling mode,in order to reduce the probability of packet collisions,a semi-persistent scheduling based on sensing is improved.Because the linear RSSI(Received Signal Strength Indicator)and RSRP(Reference Signal Receiving Power)cannot provide a sufficient basis for predicting interference,a nonlinear received power calculation method is proposed.Among them,compared with the previous received power,the new received power can more accurately predict the occurrence of interference,so the received power closer to the packet generation time should be weighted more.At the same time,in order to further reduce the probability of high PPPPpriority packet collisions,PPPP is also used as the weight of the received power calculation.Simulation results show that compared with traditional algorithms,the proposed improved algorithm can more effectively avoid the probability of high PPPP priority packet collisions,and improve the packet reception rate.