A review of selection combining receivers over Nakagami-m correlated fading channels

In this paper, selection combiner output (SCO) signal-to-noise ratio (SNR) cumulative distribution functions (cdfs) of multivariate correlated and identically distributed, and exponentially-correlated Nakagami-m fading environments for integer and non-integer fading parameter m are rigorously surveyed, and mathematically reviewed. Simulation results are obtained under two scenarios: (i) equal-channel-gain, and (ii) unequal-channel-gain. Numerical simulation, only under specific scenarios, appears to be effective to verify findings from different fading environments and different specific contributions. Schematic diagrams are employed to show (i) top-down view for progress on SCO cdfs of multivariate correlated Nakagami-m fading, and (ii) mathematical relations among existing results, from which knowledge gaps can systematically be identified. Cross-verification revealing mathematical links among the published results is shown in detail, so that unidentified special cases can be mathematically unified to their corresponding generalised cases. Useful applications of correlated fading environments are also proposed. Not just focusing on reviewing correlated fading contributions, this paper also serves as a comprehensive tutorial, consolidating key findings on this topic.