Relay outdatedness under MRC deployment

Using the distributions of bivariate exponential-correlated Nakagami-m, and Rician fading, this paper analyses opportunistic relay channel-state-information (CSI) outdatedness- written as "relay outdatedness" for brevity in this work-under two-degree-of-freedom (DoF) line-of-sight (LoS), and n-DoF nonline-of-sight (NLoS), utilising maximal-ratio-combining (MRC) deployment under Rayleigh fading environments. End-to-end system performance under NLoS outdated-CSI (oCSI) conditions are also examined. Under the proposed generalised-oCSI conditions, a conditional distribution of Rayleigh fading is first obtained, from which the corresponding distribution of Rayleigh fading under MRC deployment can be derived. Detailed discussions are given, from which MRC appears to outperform selection combining diversity under generalised-oCSI conditions. Trade-off between key parameters is identified, and explained. Monte Carlo simulation is given, which is shown to match the proposed theoretical findings.