A Novel Relay Selection and Spectrum Allocation Method for Energy Harvesting Cognitive Device‐to‐Device Network Based on Coalition Game

With the large‐scale popularity of wireless terminals, user equipment (UE) puts forward higher requirements for wireless network service quality. By using device‐to‐device (D2D) communication technology for cooperative relay transmission, any UE can be used as a potential relay UE (RUE). Making RUEs relay data for other UEs can improve the total throughput of the network. Considering the energy consumption of data relay transmission, this paper proposes a novel relay selection and resource allocation method for an energy harvesting (EH) cognitive D2D network based on a coalition game. This method first analyzes the resource allocation scheme for RUEs, either in underlay or interweave cognitive mode. Secondly, the energy harvesting incentive mechanism is used to encourage the RUE to obtain additional time to collect energy as a reward during the relay process, which can improve the willingness of the RUE to establish D2D relay links for other UEs. Finally, according to the EH incentive mechanism, the coalition comparison rules are determined. The cooperative behavior between UE and RUE is analyzed based on the coalition game, and then the relay selection problem of cognitive D2D network communication is solved. The result of the coalition game divides the user set into several subcoalition partitions, and the coalition is equivalent to the relay selection result. Simulation results show that compared with the traditional method, the proposed relay selection and resource allocation method based on a coalition game can improve the throughput of the whole network.