Performance of cooperative full‐duplex AF relay networks with generalised relay selection

Abstract

In this work, a full-duplex (FD) variable gain amplify-and-forward multi-relay cooperative-diversity system with(out) a direct path (DP) between the source and destination is studied over independent identically (non-identically) distributed slow Rayleigh fading channels. Generalised relay selection, i.e. generalised selection transmission (GST) over relays is investigated for two extreme cases; single relay selection (RS) and use of all relays, i.e. maximum ratio transmission (MRT). By developing an equivalent link, the approximated probability density function (PDF) and cumulative distribution function (CDF) of a dual-hop link with FD relay are obtained, thereafter, the adopted approximated PDF and CDF are offered. Then, approximated and asymptotic expressions for outage probability, moment generating function, and symbol error rate (SER) of GST with(out) DP are derived. Additionally, approximated ergodic capacity expressions are also obtained. All theoretical results validated by Manto Carlo simulation technique show that the proposed approximations of dual-hop link with FD relay are robust and thus can be used to analyse such systems with FD relay, RS and MRT provide close performance which is significantly better than single relay. Additionally, for equal rates, substantial reduction in SER can be obtained by FD transmission as compared to half-duplex one.