Half-Duplex and Full-Duplex AF and DF Relaying with Energy-Harvesting in Log-Normal Fading

TL;DR

This paper analyzes the performance of dual-hop relaying systems with energy harvesting over indoor log-normal fading channels, comparing half-duplex and full-duplex modes with different relaying and energy harvesting schemes, supported by analytical and simulation results.

Contribution

It provides the first comprehensive analysis of EH relaying systems over log-normal fading channels, including both HD and FD modes with AF and DF protocols, and evaluates three EH schemes.

Findings

AF relaying performs nearly as well as DF, offering efficiency benefits.

FD relaying can outperform HD if loop-back interference is low.

Increasing log-normal channel variance worsens system performance.

Abstract

Energy-harvesting (EH) and wireless power transfer in cooperative relaying networks have recently attracted a considerable amount of research attention. Most of the existing work on this topic however focuses on Rayleigh fading channels, which represent outdoor environments. In contrast, this paper is dedicated to analyze the performance of dual-hop relaying systems with EH over indoor channels characterized by log-normal fading. Both half-duplex (HD) and full-duplex (FD) relaying mechanisms are studied in this work with decode-and-forward (DF) and amplify-and-forward (AF) relaying protocols. In addition, three EH schemes are investigated, namely, time switching relaying, power splitting relaying and ideal relaying receiver which serves as a lower bound. The system performance is evaluated in terms of the ergodic outage probability for which we derive accurate analytical expressions. Monte Carlo simulations are provided throughout to validate the accuracy of our analysis. Results reveal that, in both HD and FD scenarios, AF relaying performs only slightly worse than DF relaying which can make the former a more efficient solution when the processing energy cost at the DF relay is taken into account. It is also shown that FD relaying systems can generally outperform HD relaying schemes as long as the loop-back interference in FD is relatively small. Furthermore, increasing the variance of the log-normal channel has shown to deteriorate the performance in all the relaying and EH protocols considered.