Research On Resource Allocation For D2D-Based Vehicular Communication

The communication between vehicles can effectively relieve the traffic jam and avoid road traffic accidents.With the explosive increase in the number of vehicles and variety of vehicle communications services,service quality requirements are more stringent,especially in road safety information services.More stringent requirements on the delay quality-of-service(QoS)face a challenge in the performance of the vehicular networks.In most cases,dedicated short range communication(DSRC)technology is used to realize vehicles communication in vehicular networks.However,due to the increasing number of vehicles and the dynamic change of vehicle communication topology,the traditional DSRC technology can no longer effectively meet the needs of vehicle communication.Therefore,the researchers have proposed to the mature cellular network to support vehicle communication.The emergence of device-to-device(D2D)communication technology in the 5G era has solved the problem that vehicle-to-vehicle(V2V)communication cannot be supported in cellular networks.Moreover,the underlay mode of D2 D allows V2 V communication to reuse the spectrum resources of cellular users,which greatly alleviates the current situation of spectrum resources shortage caused by many network access nodes.Thus,the safe and reliable communications of vehicles are guaranteed,and the spectrum utilization of cellular network is improved.However,the problem of same-frequency interference caused by the sharing of spectrum resources between vehicles and cellular users cannot be ignored.If effective control is not carried out,the communication between cellular user and vehicle user link will be seriously affected.Therefore,effective resource allocation methods are focused on vehicle communication in cellular networks.In terms of QoS,existing researches often do not consider the QoS requirements of users,or only consider the QoS of cellular users,and ignore the delay requirements of vehicle safety services.In view of the above problems,the dissertation content is arranged as follows:(1)To solve the problem of how to guaranteeing the delay QoS requirement of the vehicle when vehicle communication reuse cellular user’s spectrum resource,we propose a power allocation strategy with delay QoS guarantee for each D2D-based V2 V user’s requirement.The strategy takes the interference of cellular user and D2D-based V2 V user into account,and provides the effective capacity as the delay QoS guarantee.The Lagrangian dual decomposition method is used to solve the optimization problem.Numerical simulations show that compared to other schemes,the proposed scheme can improve the effective capacity of the system.(2)In the scenario where there the cellular communication users,idle users,and vehicle users are coexist,a region division method is investigated to reduce the selection range of multiplexed links in order to select the optimal multiplex links for V2 V.By using relay collaboration to solve the problems of V2 V transmission distance limitation and poor channel quality,a relay selection region limitation method based on location information is presented.An optimization function is established to maximize the system capacity.Moreover,considering the multiplexing link selection,optimal relay selection and interference control,a novel power control method is also proposed,which can guarantee the quality of communication between cellular users and vehicle users while effectively increasing the system capacity.