Research On Relay Selection And Power Allocation Based On Game Theory In D2D Communication

Device-to-Device(D2D)communication allows direct communication between User Equipments(UEs)without using the infrastructure of Base Station(BS),improving system capacity and flexibility of the local services.So it can be used as an effective complement to the cellular network.Device-to-Device(D2D)communication with a mobile terminal relaying can expand communication distance and improve the reliability.However in reality,node locations and channel aspects will dramatically affect the total system performance,so how to select a suitable relay and its power to cooperate with the D2D users is a fundamental issue for relay assisted D2D communication.Because individuals are selfish and rational among users,they can compete for resource each other,and game theory can effectively solve the confrontation and selection among decision-making bodies,therefore,the knowledge of Game Theory in relay assisted D2D communications can relatively well analysis resource allocation and sharing.Based on the above background,we study and analyze the relay selection and power allocation problems under the environment of D2D communication with decode and forward relay protocol.This paper first puts forward a relay selection algorithm based on descending price iterative auction to maximize system throughput.In the auction,D2D users are considered as bidders competing for relay nodes to obtain rate increase.We first formulate the utility function that accounts for the relay valuation from D2D and the costs for the relay power consumption.And then a maximized system utility is acquired through descending price iterative auction algorithm,meanwhile selecting the best relay.Simulation results show that this algorithm can improves the system throughput.This paper proposes a joint power allocation and relay selection resource optimization scheme based on Game Theory.This algorithm first defines user's energy efficiency as a utility function,then models and analysis the node power allocation process with the non-cooperative game theory,and proves the Nash Equilibrium of power distribution under this utility function exists and is unique.Then,based on the optimized relay power,this algorithm optimizes relay allocation through descending price iterative auction.The simulation results show that this scheme can select out optimum relay node and optimize power to maximize system energy efficiency.