Impact of Co-Channel Interference on an Underlay Cognitive Radio Network Over Nakagami-m Fading Channels

In this paper, the impact of co-channel interference (CCI) on the performance of an underlay cognitive radio (CR) network over Nakagami-m fading channels is presented and analysed. More precisely, a decode-and-forward (DF) relay protocol for a dual-hop cognitive cooperative network is considered. In this study, the impact of both the primary transmitter and CCI on the secondary system performance are considered. First, an exact expression for the equivalent signal-to-interference-plusnoise ratio (SINR) of the secondary system is obtained. Then, the corresponding exact and asymptotic cumulative distribution function (CDF) are derived. From this, the exact outage performance for the secondary network is investigated. From the results, it can be inferred that the presence of the CCI and primary network interference severely degrades the system performance. Moreover, a higher value of the shape parameter of the desired channel gives better performance and diversity gain. Finally, the analytically derived results have been supported by providing numerical and Monte Carlo simulations results.