D2D-Assisted Physical-Layer Security in Next-Generation Mobile Network

Device-to-device (D2D) communication is a promising technology to improve the next-generation mobile network. In this paper, we propose a D2D-assisted physical layer security scheme to protect D2D users from eavesdroppers. In the proposed scheme, each D2D transmission link will be protected by other D2D relay users. The relay users will manage the interference to suppress the eavesdroppers so that the eavesdroppers cannot decode the message correctly while keeping successful transmission for legitimate users. We propose to compute optimal transmitting power for each D2D relay so that it can provide the highest secrecy capacity for its data receiver. In this work, we focus on the data receivers at the edge of each D2D communication area because they receive the lowest signal-to-noise-and-interference-ratio (SINR) compared with other data receivers in the same communication area. Moreover, fairness is taken into consideration that all studied data receivers are equally protected from eavesdroppers. The simulation results demonstrate that in our proposed scheme, all D2D data receivers can achieve a high secure secrecy capacity.