Frontiers of Information Technology & Electronic Engineering
Physical layer security of underlay cognitive radio using maximal ratio combining
Hui Zhao, Danyang Wang, Chaoqing Tang, Yaping Liu, Gaofeng Pan, Tingting Li, Yunfei Chen
Abstract
We investigate the secrecy outage performance of maximal ratio combining (MRC) in cognitive radio networks over Rayleigh fading channels. In a single-input multiple-output wiretap system, we consider a secondary user (SU-TX) that transmits confidential messages to another secondary user (SU-RX) equipped with M ( M ≥ 1) antennas where the MRC technique is adopted to improve its received signal-to-noise ratio. Meanwhile, an eavesdropper equipped with N ( N ≥ 1) antennas adopts the MRC scheme to overhear the information between SU-TX and SU-RX. SU-TX adopts the underlay strategy to guarantee the service quality of the primary user without spectrum sensing. We derive the closed-form expressions for an exact and asymptotic secrecy outage probability.