Research On V2X Power Control Of Vehicle Networking Based On NOMA

The car networking system relying on 5G communication technology is expected to provide users a more comfortable and safe traffic environment with the rise of the Internet of Things and the substantial increase in car ownership.However,spectrum resources are scarce at present,so it is particularly important to further improve the communication quality in the limited spectrum resources.Non-orthogonal multiple access technology including superposition coding and serial interference cancellation technology enables subchannels to be multiplexed by more users,thus improving spectrum efficiency and channel capacity.It is now applied to the vehicle networking scenario with a more complex network communication topology as an effective method to solve the shortage of spectrum resources at this stage.This paper conducts research in two aspects: clustering and power control.For the clustering problem,first study the situation of two users in the cluster.Combining the advantages of near-far clustering and uniform channel difference clustering,the interference between users is reduced on the premise of improving the system capacity.maximize the capacity of the vehicle networking communication system.On the premise of grouping,the power allocation factor is introduced by limiting the difference of total transmission power,minimum communication rate and channel conditions between the two-user systems,and the influence of the power allocation factor on improving the total capacity of the system is studied.It is shown in simulation results that the system capacity of the two-user packet scheme and power allocation strategy proposed in this thesis is higher than that of orthogonal multiple access technology(OMA).Secondly,given that the channel resources of the two-user clustering strategy are limited,it is often difficult to meet the actual needs,so the NOMA clustering and power control strategy of multi-user vehicle networking are studied.A local traversal clustering algorithm based on channel gain is proposed.Through this algorithm,users are divided into core users,intermediate users and edge users according to the channel gain of the Internet of Vehicles.The core users and edge users are paired in sequence,and the intermediate users are traversed and added to the cluster.Reduce complexity while ensuring system capacity.An intra-cluster power control algorithm for vehicle networking is proposed based on game theory.(1)The game theory model is established to minimize the communication transmission power of each vehicle and reduce interference on the premise of ensuring the channel capacity.(2)The utility function is constructed,so that the Nash equilibrium point can be obtained for the transmission power and system channel capacity of each vehicle networking user in the game process,and the equilibrium state can be reached.(3)distributed iteration is used to obtain the optimal power allocation.It is shown in simulation results that the clustering algorithm can increase the throughput of the system,improve spectrum efficiency.And the power allocation scheme based on game theory can reduce the transmission power,interference and power consumption of users and improve the quality of service of the system on the premise of ensuring the communication capacity to the maximum extent.