Performance of two-way amplify-and-forward relaying with adaptive modulation over Nakagami-m fading channels

This paper investigates the performance of a two-way amplify-and-forward (AF) relay system with adaptive modulation over independent and non-identical Nakagami-m fading channels. The tight closed-form cumulative distribution function (CDF) expression of the instantaneous end-to-end signal-to-noise ratio (SNR) is provided. Further, approximate closed-form expression for the average spectral efficiency of the two-way AF system with adaptive modulation is obtained. Then, a tight lower bound of outage probability is derived. Finally, we use numerical simulations to verify the tightness of our analytical results.