Secrecy Outage on Transmit Antenna Selection/Maximal Ratio Combining in MIMO Cognitive Radio Networks

Abstract

This paper investigates the secrecy outage performance of transmit antenna selection (TAS)/maximal ratio combining (MRC) in multiple input multiple output (MIMO) cognitive radio networks (CRNs) over Rayleigh fading channels. In the considered system, a secondary user (SU-TX) equipped with NA (NA 1) antennas uses TAS to transmit confidential messages to another secondary user (SU-RX), which is equipped with NB (NB 1) antennas and adopts MRC scheme to process multiple received signals. Meanwhile, an eavesdropper equipped with NE (NE 1) antennas also adopts MRC scheme to overhear the transmitted information between SU-TX and SU-RX. SU-TX adopts the underlay strategy to guarantee the quality of service of the primary user without spectrum sensing. In this paper, we derive the exact and asymptotic closed-form expressions for the secrecy outage probability. Simulations are conducted to validate the accuracy of the analysis.