Research On D2D Communications Resource Allocation Algorithm Based On Game Theory And Convex Optimization

As a short-distance wireless communication technology,device-to-device(D2D)communication can improve the cellular network in term of spectrum efficiency,energy efficiency and the number of user connections with sharing the channel resources of cellular users.Therefore,D2 D communication has broad application prospects in responding to the needs of high energy efficiency(EE),high spectrum efficiency(SE),high number of nodes per unit area,and low latency in future mobile communications,and is considered to be one of the key technologies in future mobile communications systems.This article focuses on the D2 D communication resource allocation problem based on different communication performance optimization and different reuse modes.The main work of this article includes the following aspects:Firstly,for the resource allocation problem in one-to-one reusing mode with the energy efficiency of D2 D communication as the optimization goal,a power control algorithm based on partial channel state information(CSI)is proposed firstly.This algorithm takes into account of the situation that the base station(BS)cannot grasp the perfect CSI of the cross-layer interference link between the D2 D user and the cellular user when the D2 D user reuse the cellular channel.The algorithm assumes that the BS only has the statistical information of the channel fading component and the resource allocation algorithm should ensure the cellular users' transmission rate is lower than the interruption violation probability.Then the optimal transmit power combination between D2 D users and potential matching cellular users is given.Secondly,in the channel allocation problem,a fast channel allocation algorithm based on fairness guarantee is proposed.This algorithm further increases the access probability of D2 D users while improving the allocation fairness for D2 D users.In addition,the algorithm is designed to make a compromise between fairness and system EE performance.However,the performance loss is optimized with the Hungarian algorithm to modify the allocation result.So that our algorithm has both low complexity and the advantages of EE performance.Finally,the simulation results verify the advantages of our proposed joint channel allocation and power control algorithm in term of the EE of the system.Secondly,for the resource allocation problem in the multi-to-one reusing mode with the SE of D2 D communication as the optimization goal,a resource allocation algorithm based on hierarchical optimization is proposed.By decoupling the highly coupled channel allocation and power control problems into two-layer resource allocation problems,Then we solve the different layered optimization problems respectively.First of all,in the outer layer resource allocation problem,a resource allocation algorithm based on discrete power control and channel allocation is proposed for cellular users.This algorithm reduces the complexity of the entire algorithm by setting discrete transmit power options for cellular users,and makes the algorithm have a global optimal solution.When a cellular user selects a low transmission power,BS will sets a lower-capacity D2 D reusing index for the cellular user,thereby reducing the cross-layer interference caused by the D2 D user.Moreover,by setting different allocation priorities for D2 D users according to their channel gains and cross-layer interference gains,a channel allocation strategy suitable for ultra-dense D2 D communication scenarios is proposed.It should be noted that our proposed algorithm can further reduces the cross-layer interference.Finally,in the internal resource allocation problem,a power control algorithm based on non-cooperative game is proposed.The algorithm models the D2 D users who reuse the same channel as a non-cooperative game and introduces the co-layer interference cost to achieve the suppression of the co-layer interference.The Nash equilibrium solution of the game is obtained through the iterative solution of the KKT condition.Moreover,we also demonstrate the convergence of our algorithm.Simulation results show that the resource allocation algorithm proposed in this paper can improve system performance compared to existing algorithms.Finally,for the relay-assisted reusing mode,the power control problem to ensure the quality of service(Qo S)requirements of cellular users at the edge of the cell is studied.Two power control algorithms in different duplex modes are proposed.Among them,in the full-duplex mode,in view of the problem of mutual interference between cellular user signals and D2 D user signals,a corresponding optimal power control algorithm is proposed to achieve the maximal SE for D2 D communication while ensuring the transmission rate requirements of cellular users.Secondly,combining the advantages of the existing half-duplex and full-duplex modes,a hybrid-duplex relay assistant mode is proposed.In addition,the closed-form expression of the optimal transmit power is given.In this mode,by transmitting the relayed cellular signal and D2 D signal in different time slots,the signal is separated transmitting and the system performance is improved.At the same time,by introducing a time slot cutting factor,the transmission efficiency is further improved by optimizing the transmission time occupancy of different time slots.Simulation results show that the proposed D2 D relay assistant in the two different modes has different degrees of performance improvement compared with the existing comparison algorithms.