# Interference Avoidance Position Planning in UAV-assisted Wireless Communication

## TL;DR

This paper develops methods for optimal UAV positioning in interference-prone wireless communication to maximize system SIR, considering single and multiple UAV scenarios with practical constraints.

## Contribution

It introduces a theoretical framework for UAV placement to maximize SIR under various mobility constraints and proposes a distributed algorithm for multiple UAV deployment.

## Key findings

- Optimal UAV positions significantly improve SIR.
- The proposed methods reduce the number of UAVs needed.
- Distributed placement enhances system SIR effectively.

## 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 a major source of interference, the existence of which makes the problem non-trivial. First, we consider utilizing a single UAV, for which we develop a theoretical framework to determine its optimal position aiming to maximize the SIR of the system. To this end, we investigate the problem for three practical scenarios, in which the position of the UAV is: (i) vertically fixed, horizontally adjustable; (ii) horizontally fixed, vertically adjustable; (iii) both horizontally and vertically adjustable. Afterward, we consider employing multiple UAVs, for which we propose a cost-effective method that simultaneously minimizes the number of required UAVs and determines their optimal positions so as to guarantee a certain SIR of the system. We further develop a distributed placement algorithm, which can increase the SIR of the system given an arbitrary number of UAVs. Numerical simulations are provided to evaluate the performance of our proposed methods.