Performance of a simplified amplify-and-forward relaying with adaptive modulation over Rayleigh-fading channels

In this paper, we propose a simplified amplify-and-forward (AF) relaying scheme with adaptive modulation to maximize the spectral efficiency. We derive the closed-form expressions of the average spectral efficiency and outage probability of the proposed scheme over Rayleigh fading channels. The analysis results are verified by using Monte Carlo simulation. The numerical results demonstrate 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.