Research On Resource Allocation Algorithm For Internet Of Vehicle Based On NOMA

In recent years,with the rise of the Internet of things and the rapid development of intelligent transportation system,Internet of Vehicle combined with a new generation of communication technology-5G communication technology,can not only achieve wider coverage and higher communication rate,but also meet the stringent requirements of the current vehicle network communication system in terms of low delay and high reliability.However,at present,there are more and more users of vehicle network,which not only leads to the shortage of communication spectrum resources of road traffic system,but also increases the consumption of energy.The application demand of massive traffic equipment access and Internet of Vehicle users is growing,which requires the system to have low delay and high reliability,at the same time,it needs to further improve the communication quality and system energy efficiency in the limited spectrum resources.Non-orthogonal multiple access technology(Non-Orthogonal Multiple Access,NOMA)relies on superimposed coding and serial interference cancellation technology,which can enable more users to multiplex subchannels,thus greatly improving the spectrum efficiency and channel capacity.Internet of Vehicle combined with nonorthogonal multiple access technology can not only meet the needs of low delay and high reliability of Internet of Vehicle,but also greatly improve the system speed and energy efficiency of Internet of Vehicle.This thesis focuses on the resource allocation of the disembarkation network system in the NOMA framework.The main contents and innovative work of this thesis are as follows:In order to meet the application requirements of low delay and high reliability of Internet of Vehicle based on NOMA,the system and speed maximization of NOMA vehicle network are studied in this thesis.Because the problem belongs to NP-hard problem,the problem is divided into user clustering problem and power allocation problem to solve.For the problem of user clustering in vehicle network,the system performance limit of NOMA is determined by the channel difference between subchannel superimposed users.In order to maximize the channel difference of all vehicle network users,this paper proposes a user clustering algorithm based on Kuhn-Munkres algorithm.For the power allocation problem of vehicle network users,after clustering is completed,the optimization problem of maximizing vehicle network system and speed is treated as an unconstrained problem by penalty function method.Then combined with the particle swarm optimization algorithm,a new power allocation algorithm is proposed to solve the optimization problem.Finally,through the experimental simulation,compared with other user clustering algorithms,the user clustering algorithm proposed in this thesis can improve the spectrum efficiency and effectively maximize the sum rate of the vehicle network system.Compared with the existing power allocation algorithms,the power allocation algorithm proposed in this thesis can greatly improve the system and speed of the vehicle network system,and the convergence speed is faster.In order to meet the requirements of energy-saving communication in road traffic system,aiming at the downlink of NOMA vehicle network,in order to maximize the energy efficiency of vehicle network system,a sub-channel-user matching algorithm and power allocation algorithm are designed.First of all,the rate quality factor is introduced to distinguish the user channel quality.According to the channel quality of users,a subchannel-user matching algorithm based on channel equalization matching is designed to determine the matching problem between users and subchannels,and then the convex difference(Difference of Convex,DC)programming algorithm is used to solve the subchannel power allocation factor and cross-subchannel power allocation problem.Finally,the experimental results show that the joint subchannel-user matching and crosssubchannel power allocation algorithm proposed in this thesis greatly improves the system capacity and energy efficiency of the vehicle network system compared with the OFDMA scheme;compared with the fractional order power allocation algorithm and the equal power subchannel power allocation algorithm,the cross-subchannel power allocation algorithm proposed in this thesis is always better than other algorithms in improving the performance of the vehicle network system.