Interference Avoidance Position Planning in Dual-hop and Multi-hop UAV Relay Networks

Abstract

We consider unmanned aerial vehicle (UAV)-assisted wireless communication employing UAVs as relay nodes to increase the throughput between a pair of transmitter and receiver. We focus on developing effective methods to position the UAV(s) in the sky in the presence of interference in the environment, the existence of which makes the problem non-trivial and our methodology different from the current art. We study the optimal position planning, which aims to maximize the (average) SIR of the system, in the presence of: i) one major source of interference, ii) stochastic interference. For each scenario, we first consider utilizing a single UAV in the dual-hop relay mode and determine its optimal position. Afterward, multiple UAVs in the multihop relay mode are considered, for which we investigate two novel problems concerned with determining the optimal number of required UAVs and developing an optimal fully distributed position alignment method. Subsequently, we propose a costeffective method that simultaneously minimizes the number of UAVs and determines their optimal positions so as to guarantee a certain (average) SIR of the system. Alternatively, for a given number of UAVs, we develop a fully distributed placement algorithm along with its performance guarantee. Numerical simulations are provided to evaluate the performance of our proposed methods.

Optimal Jammer Placement in UAV-assisted Relay Networks

“…In the context of UAV relay networks, we were among the first to study the placement optimization and trajectory design for UAV relays to evade the interference caused by the jammers [9]- [12]. Considering a major source of interference (MSI), the optimal placement of the UAV relays along with identifying the minimum number of required UAVs to satisfy a desired communication quality are studied in [9], [10]. A joint power allocation and trajectory design is proposed in [11], [12] to evade the interference caused by another established wireless network.…”

Dynamic Interference Management for UAV-Assisted Wireless Networks

“…In this work, it is assumed that the UAVs are hovering at an identical fixed altitude during the transmission. As a follow-up work for [21], in our recent work [22], [30], we studied the optimal position planning of UAV relays between the transmitter and the receiver, which coexist with a major interferer in the environment. In this work, we investigated the following two new problems: i) identifying the minimum required number of UAVs and their optimal positions to satisfy a given SIR of the system, ii) developing a distributed algorithm to maximize the SIR of the system requiring message exchange only between adjacent UAV relays.…”