On the performance of transmit antenna selection in multiuser asymmetric RF/FSO system under generalized order user scheduling

Abstract

In this paper, the performance analysis of transmit antenna selection on a multiuser asymmetric RF/FSO system under generalized order user scheduling is investigated. A dual-hop system with one source, one relay and multiple FSO users at destination is considered without direct link between the source and destination. The RF link is subjected to Nakagami-m fading and FSO links follow Exponential Weibull (EW) distribution. Using the amplify-and-forward (AF) channel-state-information (CSI) based gain relay protocol, the equivalent cumulative distribution function (CDF) end-to-end SNR at the destination is derived and used to obtain the analytical expression for the system outage probability. By utilizing the derived statistics, the closed-form expression for the system average bit error rate (ABER) is then derived through the Gauss–Laguerre quadrature rule and second kind Stirling number. Moreover, the results demonstrate that the atmospheric turbulence significantly degrades the system performance and increase in the number of source transmit antenna offers the system better performance. Also, the system performance is deteriorated by increasing the orders N or decreasing the number of user K. The accuracy of the derived expressions is validated through Montel-Carlo Simulations.