Ground Experiment of Full-Duplex Multi-UAV System Enabled by Directional Antennas

TL;DR

This paper presents ground experiments validating a full-duplex multi-UAV communication system that uses directional antennas and UAV position control to reduce interference, aiming to improve spectrum efficiency without complex hardware.

Contribution

It demonstrates the feasibility of interference cancellation in multi-UAV systems using directional antennas and position control, avoiding energy-intensive self-interference cancellers.

Findings

Interference power is effectively reduced with directional antennas.

Achieved channel capacity aligns with design expectations.

Different antenna configurations impact interference and capacity.

Abstract

A high performance multi-UAV communication system, which bridges multiple UAVs and ground station, is one of the key enablers to realize a variety of UAV-based systems. To address the issues such as the low spectrum efficiency caused by the co-channel interference, we have proposed a spectrum-efficient full-duplex multi-UA V communication system with low hardware complexity. In this paper, on-ground experiments are conducted to confirm the feasibility and effectiveness of the key feature of the proposed system, i.e., co-channel interference cancellation among UAVs by directional antennas and UAV position control, instead of energy-consuming dedicated self-interference cancellers on UAVs in traditional full-duplex systems. Channel power of interference link between a pair of two UAVs reusing the same channel is measured, and the achievable channel capacity is also measured by a prototype system implemented by software-defined radio devices. The results of different antennas and different antenna heights are also compared. The experimental results agree well with the designs and confirm the feasibility and effectiveness of the proposed system. This ground experiment is a work in progress to provide preliminary results for the multi-UAV-based experiments in the air in the future.