Robust Resource Optimization And Power Control For D2D Networks Under Imperfect Channel Information

According to the latest statistics,the data flow has increased about 1000 times in the past 10 years.This makes the traditional cellular network structure face great challenges.Device to device(D2D)communication has great potential in improving spectrum utilization,reducing transmission delay,offloading traffic,expanding bandwidth,coverage and reducing system energy consumption.However,the introduction of D2D communication into traditional cellular networks also faces some problems and challenges:How to reduce the harmful interference in the system and increase the total rates of the system;how to deal with the imperfect channel information in the actual communication environment.In view of the above problems,this paper proposes the following solutions:(1)Aiming at the low utilization of spectrum resources in traditional cellular network under imperfect channel,D2D communication technology is introduced into traditional cellular network.Part of the channel information is considered to be imperfect,that is,the communication link from macro user to the D2D user(CU-D link),and the communication link between D2D transmitter and D2D receiver(D-D link).Furthermore,a joint channel selection,admission control and power allocation problem for D2D wireless network resource optimization is constructed.Finally,convex optimization and geometric analysis are used to obtain the optimal power solutions of macro user and D2D user.The total communication rate of the system is effectively improved.(2)Aiming at the problem of poor communication quality of edge D2D users in D2D unicast communication system under imperfect channel.A robust power allocation strategy based on Stackelberg game is proposed.In this chapter,we consider the imperfect model in which the instantaneous channel state information(CSI)of all communication links obey Truncated Gaussian distribution,and the macro user and D2D user are clustered.In the non cooperative game,BS is regarded as the leader,while D2D users are regarded as followers.The outage probability constraint method is used to guarantee the Qo S of macro users.Finally,the Lagrange multiplier method is used to obtain the optimal solution.The simulation results show that the improved algorithm can improve the total communication rates of the system.(3)In the model of D2D multicast communication(D2MD)system under imperfect channel,multiple D2D users reuse one authorized user's spectrum resource at the same time,which causes serious signal interference.A D2MD communication interference management strategy based on robust non cooperative game is proposed.The aggregation interference of D2D users is constrained to maximize the profit of BS.Finally,the distributed algorithm is used to reduce the information exchange between systems.Simulation results show that the proposed D2MD communication interference management strategy based on robust non cooperative game has lower algorithm complexity and stronger robustness.