Outage analysis of dual-hop OFDM relay system with subcarrier mapping in Nakagami-m fading

This paper presents the analysis of outage probability for dual-hop orthogonal frequency division multiplexing (OFDM) relay system with ordered subcarrier mapping (OSM) in Nakagami-m fading. Accurate closed-form expressions are derived for the outage probability while considering a fixed gain amplify-and-forward (AF) relay system. Two special cases of Nakagami-m fading, i.e., Rayleigh (m = 1) and one-sided Gaussian (m = 1/2) are, specifically, focused with capacity-enhancement subcarrier pairing scheme and their performance is analyzed for balanced links, i.e., when SNR of each hop is same, as well as for unbalanced links, i.e., when the SNR of second hop is one-half of the first hop SNR, scenarios. The later which is known as the worst case of fading is, especially, focused for various analysis of the system. The variation of outage probability is shown for different values of fading severity (m) and number of resolvable paths (L) parameters. Numerical results validate analytical work in Nakagami-m fading channel model.