Outage performance of Nth-best antenna selection diversity systems with co-channel interference and outdated channel information

In this paper, we evaluate the outage performance of space diversity systems with the Nth-best antenna selection scheme in the presence of co-channel interference (CCI) and outdated channel information. In this paper, we first derive the cumulative distribution function (CDF) of the end-to-end (e2e) signal-to-interference plus noise ratio (SINR) at the selection scheme combiner output. This CDF is then used to derive a closed-form expressions for the e2e outage probability for the independent non-identically distributed (i.n.i.d.) and independent identically distributed (i.i.d.) cases of diversity branches and interferers' channels. In the analysis, the channels of the desired user and the interferers are assumed to follow Rayleigh distribution. Furthermore, to get more about system insights, the outage performance is studied at high signal-to-noise (SNR) regime where approximate expressions for the outage probability, diversity order, and coding gain are derived and analyzed. Monte-Carlo simulations are provided to validate the derived analytical and asymptotic expressions. Main results illustrate that with a fixed number of interferers of power not scaling with SNR, the system can still achieve diversity gain when more receive antennas are used. Also, findings show that the diversity order of the system linearly increases with decreasing the order of the selected antenna, and vice versa decreases.