Wireless-Powered Full-Duplex UAV Relay Networks Over FTR Channels

Abstract

A thorough understanding of fundamental limits of wireless-powered unmanned aerial vehicle (UAV) relay networks in millimeter waves is still missing. We narrow this gap by investigating the outage performance of a UAV-assisted wireless network over fluctuating two-ray (FTR) channels. The FTR fading model is particularly appealing since well characterizes the wireless propagation in a wide range of frequencies, including those in millimeter waves. The proposed setup consists of a source-destination pair communicating with the assistance of a UAV, which is a wireless-powered relay station operating in full-duplex mode under the amplify-and-forward protocol. For the wireless energy harvesting at the UAV, wireless power transfer (WPT), simultaneous wireless information and power transfer (SWIPT), and self-recycling energy techniques are employed together. To characterize the system outage probability, we obtain an integral-form expression derived from an approximate analysis and a simple closed-form expression derived from an asymptotic analysis at the high signal-to-noise ratio (SNR) regime. Monte Carlo simulations are provided to validate the correctness of our theoretical results and provide insights on the network performance in terms of key system parameters. Interestingly, obtained results show that the FTR fading parameters corresponding to the first hop and second hop play no role on the system outage performance at high SNR. Instead, it is mainly governed by the effect of the residual self-interference at the UAV, leading to outage floors.Index Terms-Fluctuating two-ray, full duplex, mmWave communications, outage probability, simultaneous wireless information and power transfer, unmanned aerial vehicle.

A Survey on Multiuser SWIPT Communications for 5G+

“…UAV-assisted SWIPT, as an upsurge of recent research topic, has gained momentum rapidly. The existing UAV-enabled SWIPT literature can be broadly divided into three categories, which are cooperative SWIPT networks [217]- [229], multicasting SWIPT networks [230]- [247] and millimeter-wave (mmWave) SWIPT networks [199], [248]- [253]. Apart from these, there are a few works in the literature that facilitate disaster aware clustering and association [254], and secure information and power transmission [255].…”

“…Millimeter-wave bands give key enablers for the revolutionary facilities with the wide swaths of unused and unexplored spectrum. Towards this, the available literature has presented a few mmWave UAV-enabled SWIPT studies that can be basically grouped as single-user [250], [253] and multiuser communication [199], [251], [252]. These studies are summed up in Table VI.…”

“…These studies are summed up in Table VI. A similar work [253] has been studied an FD-enabled AF-based UAV-aided cooperative SWIPT communication system over fluctuating two-ray fading model that well characterizes the wireless channels in a wide range of frequencies, i.e., millimeter waves. The authors, in [250], investigated a downlink secure mmWave UAV-aided SWIPT system, where the UAV as an aerial BS exploits the directional modulation scheme based on a random frequency diverse array.…”

Performance and User Association Optimization for UAV Relay-Assisted mm-Wave Massive MIMO Systems

“…Here, it is considered that the UAV relay position remains unchanged (or that the UAV speed is sufficiently low) during a certain time interval in order to serve the ground users. Nevertheless, power-limited constraint, which affects the flight time can be taken into account for future studies, and there are some related works that can be found in [59], [60]. Throughout this paper, we assume that problem (26) is always feasible when the QoS requirement of each user will be satisfied if a ij = 1.…”