Average outage rate and average outage duration of adaptive selection DF relaying in cooperative networks

Performance metrics such as outage probability, average error rate and capacity have been studied in cooperative diversity systems by a large number of papers. However, the second-order statistics properties in cooperative diversity systems have not been completely investigated. In this letter, we investigate the second-order statistics properties of an adaptive selection decode-and-forward relaying (SR) cooperative diversity system. We focus on two performance metrics: average outage rate (AOR) and average outage duration (AOD). The accurate closed-form approximations for the AOR and AOD performances are derived using Gauss-Legendre quadrature. The accuracy of our approximations is validated by the Monte-Carlo simulations. Furthermore, we compare conventional SR protocol and adaptive SR protocol in AOR and AOD. It is shown that adaptive SR protocol has a better performance in AOR but two protocols have similar performance in AOD.