Moments of the SNR of two-hop multichannel relaying with subchannel pairing

In this paper, we analyze moments of instantaneous signal-to-noise ratio (SNR) in a multichannel relay system with subchannel pairing (SP) over Rayleigh fading environments. With aid of order statistics, new unified expressions of moments of the SNR are derived in closed-form for three SP cases, i.e., ordered subchannel pairing (OSP), reversely ordered subchannel pairing (ROSP) and non-subchannel pairing (NSP). More specifically, we obtain moments of the SNR in a decode-and-forward (DF) relay system for three power allocation schemes: uniform power distribution, water-filling power assignment and power adaptation with truncated channel inversion policy. Due to mathematical tractability, we only cope with SNR moments in an amplify-and-forward (AF) relay system for uniform power allocation scheme. Simulation results indicate the accuracy and effectiveness of our theoretical formulas.