Research On Resource Allocation Algorithms In D2D And NOMA Assisted Cellular Communication System

Device-to-Device(D2D)and Non-Orthogonal Multiple Access(NOMA)are the key technologies of 5th Generation/Beyond 5th Generation(5G/B5G)network.Different resource sharing strategies can effectively improve the capacity and spectral efficiency of the system,but also introduce the co-frequency interference.Therefore,in order to maximize the efficiency of D2D and NOMA,it is of great scientific significance to design an effective resource allocation algorithm to reduce co-frequency interference and improve system performance.This thesis focuses on the resource allocation of D2D and NOMA assisted cellular communication system in the following two aspects:Firstly,towards the resource sharing scenario of multiple D2D pairs and uplink multi-user multiple-input multiple-output(MU-MIMO)cellular,a power control algorithm based on maximizing the number of shared D2D pairs is proposed.All users must meet the communication quality requirements.Then,the optimization problem is equivalent to the system interference minimization problem with cellular users as the primary users.In order to solve this problem,the algorithm is decoupled into uplink MU-MIMO cellular users identification method and shared D2D pairs identification method,which are solved by convex optimization successively.The simulation results prove that the proposed algorithm can support more D2D pairs to share resources with cellular users.Secondly,a resource allocation algorithm based on system sum rate maximization is proposed for full duplex NOMA cellular communication system.The algorithm combines user pairing and power allocation to maximize the system sum rate under the constraints of the minimum transmission rate and limited transmission power of all users.In the solution process,the strong and weak users are paired according to the channel gain information.Then,by further constraining the conditions for the establishment of full duplex NOMA communication,the theoretical value of the power allocation factor range is derived.And the transmission powers of base station and the paired users within this range are optimized to maximize the system sum rate.Simulation results show that the full duplex NOMA communication has better system performance than the full duplex Orthogonal Multiple Access(OMA)communication.In conclusion,the resource allocation algorithm of D2D and NOMA networks proposed in this thesis can effectively suppress co-frequency interference and improve the spectral efficiency of the system,providing technical support for the application of D2D and NOMA technologies in the next generation mobile communication system.