Physical Layer Security for TAS/MRC Systems With and Without Co-Channel Interference Over $\eta$–$\mu$ Fading Channels

In this paper, the secrecy performance of transmit antenna selection/maximal ratio combining systems in the absence and presence of co-channel interference (CCI) over η-μ fading channels is considered. In particular, closed-form expressions for the secrecy performance are derived. To investigate the secrecy diversity gain, we also provide asymptotic secrecy outage analysis. Results show that the achievable secrecy diversity gain is 2μNT ND regardless of the number antennas of the eavesdropper NE, where NT and ND are the number antennas of the legitimate transmitter and receiver, respectively. Furthermore, it shows that the asymptotic secrecy performance is only dependent on the ratio γE /γD for both the systems with and without CCIs, regardless of the values of PI, where PI is the power of the interference. Finally, we provide some numerical examples to illustrate the presented analytical expressions.