Performance of Selection Combining Amplify-and-Forward Relaying with Adaptive Modulation over Nakagami-m Fading Channels

This paper investigates the performance of selection combining (SC) amplify-and-forward (AF) relaying with adaptive modulation to maximize the spectral efficiency. We derive the closed-form expressions of the average spectral efficiency and the outage probability of the proposed scheme over independent and non-identical Nakagami-m fading channels. The analysis results are verified by using Monte Carlo simulations. Our results indicate that the proposed scheme not only has simplified receiver architecture, but also can offer similarly high spectral efficiency as the MSE-AM scheme proposed in [1], when the relay link is stronger enough than the direct link.