Outage analysis of incremental opportunistic regenerative relaying with outdated CSI under spectrum sharing constraints

In this paper, we investigate the impact of using outdated channel state information for incremental opportunistic relay selection in a spectrum sharing cognitive network. In our work, we present the outage performance of two schemes where the power allocation is based on the instantaneous outdated channel state information and the statistical knowledge of the interference links, referred to as CSI-based scheme and LF-based scheme, respectively. By investigating the effect of the rank of the selected relay and the correlation coefficients imbalance on outage performance, a comparison reveals that LF-based scheme outperforms its CSI-based counterpart. We validate our analysis with simulation results in a Rayleigh fading environment.