Analyzing the physical layer security performance of the ANC system

Based on the theory of physical layer security (PLS), this paper demonstrates that analog network coding (ANC) has ability to improve the PLS performance of the two-way relay channel against different kinds of eavesdroppers. In this paper, we define the security and unsecurity region and derive the system security capacity with ANC and traditional transmission schemes. In particular, we consider external and internal eavesdroppers respectively. Besides, we investigate the factors influencing the ANC system PLS performance. The simulation results show that ANC can greatly improve the system PLS performance against an external eavesdropper, and ensure that an internal eavesdropper cannot decode any confidential information. Furthermore, the ANC system PLS performance can be slightly improved by increasing signal source's transmission power level and eavesdropping channel's noise level.