Adaptive Direction Control for UAV Full-Duplex Relay Networks Using Multiple Directional Antennas

Takahiro Matsuda,Takefumi Hiraguri,Akihiro Nakao,Kentaro Nishimori,Megumi Kaneko,Tomotaka Kimura

doi:10.1109/access.2020.2992293

Abstract

We consider a UAV (Unmanned Aerial Vehicle) relay network whereby each UAV senses data and forwards it to dedicated ground stations by means of multi-hop relaying. In particular, we focus on a UAV relay network with a simple yet realistic linear topology for which we propose an adaptive direction control scheme to achieve a high throughput performance. In the proposed scheme, each UAV, equipped with multiple directional antennas, selects either the Decode-and-Forward (DF) straight relaying method or the orthogonal relaying method, for full-duplex data transfer, i.e., data is transmitted and received simultaneously on the same frequency, but at different antennas. The originality of our proposed method is to make each UAV rotate relatively to the position of its neighbouring UAVs, in order to optimize its antenna radiation direction, according to the selected relaying method. The key advantage of the proposed method is that signal direction can be controlled without the need of heavy adaptive signal processing as in conventional beamforming techniques. In order to clarify the decision parameters for selecting a relaying method, we first evaluate the throughput performance of the two-hop relay network under the severe interference conditions of UAV networks, and next, propose a procedure for selecting a multihop relaying method. Numerical experiments show that the proposed scheme enables to achieve a high throughput performance, with low computational costs.

Highlights

Wireless networks based on UAVs (Unmanned Aerial Vehicles) have been attracting a lot of attention and various kinds of applications have been investigated so far, such as environmental monitoring [1], [2], disaster management [3], wireless sensor networks [4]–[6], flying base stations [7]–[10] and FANETs [11]
We propose a low-complexity, low-burden data relaying scheme based on adaptive UAV direction control, for a UAV relay network where multiple UAVs relay their sensed data to a fixed ground station through multi-hop links The key feature of the proposed method is to equip each UAV with simple multiple directional antennas and to exploit full-duplex relaying, with the goal of enhancing the achievable throughput of UAV relay networks
In this work, we have considered the problem of throughput enhancement in a multihop UAV relay network where UAVs forward their sensed data to a ground station, through multihop UAV links

Summary

INTRODUCTION

Wireless networks based on UAVs (Unmanned Aerial Vehicles) have been attracting a lot of attention and various kinds of applications have been investigated so far, such as environmental monitoring [1], [2], disaster management [3], wireless sensor networks [4]–[6], flying base stations [7]–[10] and FANETs (flying ad hoc networks) [11]. It is worth noting that this proposed adaptive UAV direction control technique lends itself naturally to the specific operations of UAVs, whose positions/rotations can be controlled rather while the cost of advanced signal processing is hardly bearable by individual UAVs. to clarify the decision parameters for selecting the best relaying method, we first evaluate the throughput performance of a simple two-hop relay network. This means that we can select a relaying method solely based on α and d/L, which represent network configuration parameters as they reflect well the nodes’ relations

THROUGHPUT PERFORMANCE OF TWO-HOP RELAY NETWORKS

DECISION TABLE FOR DIRECTION CONTROL

THROUGHPUT PERFORMANCE OF MULTIHOP RELAY NETWORKS

CONCLUSION