Device-to-Device Cellular Physical Layer Security Strategy Based on Social Attribute Matching

Device-to-Device (D2D) communication transmits the data between user terminals directly without being forwarded by the base station (BS), which distributes the load of the cellular network. When cellular users (CUs) and D2D users (DUs) share link resources in multiplexing mode, this can improve the spectrum utilization but may be prone to co-channel jamming. And legitimate users may be eavesdropped in actual communication. In order to address these problems, D2D users can assume the role of cooperative jamming devices to increase the discrepancy between cellular links and eavesdropping links, thereby enhancing the reliability of CUs. However, traditional cooperative jamming strategies fail to account for the selfishness of D2D nodes. In this thesis, we propose the use of content similarity, topic similarity and social trust among legitimate users as a means of representing the social intimacy among nodes. Based on this, the communication nodes can select the free and closer D2D users to send jamming signals to eavesdroppers, thereby improving the physical layer security (PLS) of the system. Taking into account the social relationship between devices, we propose an optimal resource matching strategy between D2D users and CUs to maximize the system sum utility using the Kuhn—Munkres (KM) algorithm. The simulation results demonstrate that our strategy outperforms existing strategies in optimizing the performance of the PLS.