Abstract
Device-to-device (D2D) communication is a promising technology which can improve the spectrum efficiency of cellular networks. Despite abundant research on resource allocation and interference cancellation for D2D communication, few works discuss how D2D is realized within cellular communication. In this paper, we propose a symmetric cooperative communication architecture combining security and energy efficiency, in which the users in 5G cellular networks can adaptively select the communication mode among cellular, direct D2D, and relay-assisted D2D communication according to the energy-consumption requirement. Considering the security aspect, we propose a novel relay selection strategy based on the asymmetry of social networks for the architecture. Firstly, we reduce the number of candidate relay devices based on energy consumption, the devices’ battery status, and the devices’ state. Then, an appropriate relay device is selected according to the proposed criteria, combining energy consumption, wireless channel quality, proximity prestige, and spreading ability. Simulation results reveal that, compared with conventional cellular communication and D2D communication, the proposed architecture can increase the number of users accessing the cellular networks simultaneously, improving the throughput and the security of data transmission. It can also significantly reduce the energy consumption as well as outage probability.