Performance Analysis of Physical Layer Security for Cognitive Radio Non-Orthogonal Multiple Access Random Network

This paper analyzes the security communication performance of secondary user communication pairs in Cognitive Radio Non-Orthogonal Multiple Access (CR-NOMA) networks, where interference sources and eavesdropping nodes are randomly distributed. The stochastic geometry theory is used to model the eavesdropping nodes and the interfering nodes as a homogeneous Poisson Point Processes (PPP). Firstly, to ensure the reliability of the primary user communication pairs, the power allocation coefficient set of the sender is obtained, and the closed expressions of the connection outage probability and the secrecy outage probability of the secondary user are further obtained. Then, the variation of the power distribution coefficient with the constraint of the primary user's reliability is analyzed. Finally, the relationship between outage probability of secondary user communication pairs and the density of the eavesdropping nodes and the transmission power is studied. The research shows that the enhancement of interfering signal reduces the reliability of the system, but brings about a significant improvement of security performance. The simulation results verify the correctness of the theoretical analysis.