Opportunistic Relay Selection for Physical Layer Security Enhancement in Internet of Things

Internet of Things (IoT) is playing an important role in our lives. It connects lots of embedded devices, which can deal with very complicated and difficult tasks to facilitate our work. However, the security of IoT faces many challenges due to the wireless broadcasting nature and the energy constraint of the physical objects. In order to provide a secure environment for IoT, in this paper, we investigate two opportunistic relay selection schemes to further enhance physical layer security, which are single relay selection(SRS) and multi relay selection(MRS) respectively. We analyze the outage probability (OP) and intercept probability (IP) as well as the system tradeoff performance (STP) for SRS and MRS under Nakagami-m fading channel. Simulation results show that the OP and IP of MRS are all better than that of SRS. Besides, the STP for MRS is also more perfect than that of SRS. What's more, the STP of these two opportunistic relay selection schemes improve with the increasing of relay numbers.