Outage performance of space diversity systems with Nth-best receive antenna selection and co-channel interference

In this paper, we evaluate the outage performance of space diversity systems with the N^th-best antenna selection scheme and co-channel interference (CCI). 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 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 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 is linearly decreasing with increasing the order of the antenna, and linearly increasing with decreasing it.