Diversity scheme for unmanned aerial vehicles based flying ad-hoc network

Abstract

Flying ad-hoc networks (FANETs) using unmanned aerial vehicles (UAVs) are becoming popular in various civilian and military applications. However, typical features of UAVs make the channels of FANET intermittent and unreliable. The cooperation of UAVs needs to be enhanced to meet the requirements of the applications and areas of deployment. We propose a buffer-aided incremental cooperative relaying scheme working in two phases and providing link and packet diversity on amplify-and-forward aerial relays in area monitoring applications. Several challenges in the context of FANET communication are considered to provide data dissemination with quality. The closed-form expressions for the system outage probability, maximal ratio combining, and diversity gain on Rayleigh fading channels are studied. The analytical results are given as asymptotic expressions based on the upper bound on the end-to-end signal-to-noise ratio (SNR). The analysis is extended to a scenario where multiple relaying UAVs contribute to cooperative relaying. The simulation results reveal that the proposed buffer-aided communication scheme improves system performance compared to buffer less, compulsory direct, and compulsory indirect settings. The SNRs, relay buffer sizes, channel information rates, power allocation factors, and relays count demonstrate a strong impact on system reliability and need proper selection while designing such systems.