Secure Communications with Secondary User Selection in Underlay Cognitive Radio Networks
Mian Qin, Shouyi Yang, Zhuo Han, Ruizhe Zhang, Hao Jiang Deng · 2018
This paper investigates the effect of multiuser gain provided by the secondary user selection on the secrecy performance of the primary users. We propose a simple secondary user selection scheme and derive a closed-form lower bound of the achievable ergodic secrecy rate of the primary users. In the high signal-to-noise ratio (SNR) regime, asymptotic result shows that the multiuser gain scales logarithmically with the number of the secondary users for a fixed interference temperature. When there is no interference temperature constraint, more multiuser gain can be achieved as the secondary user transmits with a higher power. Theoretical and simulation results show that the interference from the secondary users is helpful and the multiuser gain enhances the security of the primary users greatly.