Ergodic Capacity Analysis for Interference-Limited AF Multi-Hop Relaying Channels in Nakagami-m Fading

An analytical characterization of the ergodic capacity of interference-limited multihop wireless networks with amplify-and forward (AF) relaying is presented. In our analysis, we consider that transmissions are performed over Nakagami-m fading where channel state information is only known at the receiving terminals. We derive an exact expression for the ergodic capacity by exploiting the moment generating function (MGF) of the inverse signal-to-interference ratio (SIR). The result is applicable for arbitrary numbers of interfering signals at the receiving terminals and can be efficiently evaluated. Furthermore, considering the special case of dual-hop transmission, we propose a more refined characterization where the high-SIR capacity is expanded as an affine function. The zero-order term or the power offset for which we find insightful closed-form expressions, is shown to play a chief role in understanding the impact of interference and power on the system's capacity. Finally, some simulation results sustaining our analysis are provided.