Research On Resources Scheduling For C-V2X Based Vehicle Platoon Systems

With the wide application of the 5th generation mobile communication(5G),cellular vehicle-to-everything(C-V2X)has evolved to 5G-V2 X,supporting advanced traffic scenarios such as vehicle platoon.Thanks to the small intra-platoon distance and consistent behaviors,platoon can bring many benefits,such as road capacity and driving security increment,and communication performance enhancement.However,the platoon-based driving pattern brings many complex communication types and strict communication requirements,hindering the practical application of platoon.This paper studies the problems of platoon manager selection,communication resource allocation and handover between roadside units(RSUs)for platoons in 5G-V2 X scenario.In the single RSU scenario,this paper studies the dynamic selection of platoon manager and communication resource optimization in the finite block length regime.When studying the platoon manager selection problem,a optimization problem is established to maximize the average received signal-to-noise ratio(SNR)of platoon members.The closed-form expression for the index of platoon manager is derived,and a dynamic platoon manager selection(DPMS)algorithm is proposed.The proposed DPMS algorithm effectively improves the received SNR of platoon members and the fairness of intra-platoon communications,and enhances the ability of the platoon structure to dynamically adapt to the traffic environment.The platoon safety-related data has limited size and ultra-reliable and low-latency requirements.Therefore,this paper jointly optimizes the coding rate,transmission power and channel allocation in the finite block length regime to minimize the intra-platoon multicast latency.The closed-form expressions for the optimal finite block length coding rate and optimal transmission power are derived,and a subchannel multiplexing criterion based on channel state information is proposed.Based on the theoretical findings,a joint resource allocation and coding rate optimization(JRACRO)algorithm is proposed.The proposed JRACRO algorithm can reduce the intra-platoon multicast latency and ensure the effective throughput.In the multi-RSUs scenario,this paper studies the problem of platoon handover between adjacent RSUs.To avoid the intra-platoon and inter-cell interference of communication links between platoon members,the number of platoon vehicles in the range of RSUs is introduced as a key parameter of the handover process,and a multi-RSUs cooperative spectrum allocation scheme is proposed.A seamless handover scheme based on cooperative multipoint transmission(Co MP)is proposed,and a corresponding joint block length and transmission power optimization algorithm is proposed for the Co MP mode of RSU-platoon link.Simulation results show that the proposed handover scheme can effectively reduce the interference and ping-pong effect during the handover process,and improve the communication quality when the platoon is located at the edge of the range of RSU.