Research On Resource Allocation Algorithm Of D2D Communication In LTE-A System

With the advancement of technology,the popularity of mobile devices that support data services(especially smart phones)are increasing,leading to explosive growth in mobile traffic.Wireless spectrum resources are becoming increasingly scarce,communication needs of users have grown rapidly.which bring a huge challenge for LTE-A systems in terms of technology and operations.Wireless communication must satisfy diverse requirements,including requirements for throughput,quality of service,and delays.Therefore,D2 D communication technology has emerged.D2 D communication is a new technology for direct communication between two close user terminals without base station forwarding.The introduction of D2 D communication is not only improves spectrum utilization and system throughput,but also applies to different scenarios to solve blind spot communication difficult problem.This dissertation mainly studies the allocation of D2 D communication resources to suppress interference under the LTE-A system.In view of D2 D communication users multiplexing single-cell cellular uplink resources and cross-cell uplink resources in two scenarios about the interference,a suitable resource allocation algorithms to reduce interference is proposed.The main research content is summarized as follows:1.Aiming at the problem that the interference of the same frequency in the hybrid network system of cellular users and D2 D users.A resource allocation algorithm for D2 D communication based on price competition is proposed.The algorithm not only considers using base station pricing to reduce interference to cellular systems,but also joint base station-side interference tolerance to constrain the interference power.Firstly,the problem is formulated as a "non-cooperative game" process,the utility function model is used to analyze the profit of D2 D users and the interference to the base station,so as to adjust the transmission power to maximize the overall system revenue.Secondly,updating the interference and the reuse price through the communicating D2 D user;Finally,the water injection algorithm is used to optimize the price using the Lagrangian condition.2.To solve the interference problem of establishing D2 D communication in cross-cell edge,a resource allocation algorithm based on outage probability incross-cell is proposed.The algorithm firstly analyzes the user's SINR according to the system model and then sets the outage probability threshold.Secondly,the outage probability of communication between the D2 D user and the cellular user is traversed.When the outage probability is less than a certain threshold,making the reusable cellular user limited to such an collection area.Finally,the degree of user's interference to D2 D user receiver is represented by the cumulative outage probability,removing large interference cellular users,identifying the final multiplexed cellular sources of the D2 D user.