Enabling UAV Cellular with Millimeter-Wave Communication: Potentials and Approaches

TL;DR

This paper explores the potentials of millimeter-wave communication for UAV cellular networks, addressing challenges like beamforming, Doppler effects, signal blockage, and UAV positioning to enhance high-data-rate ad hoc communications.

Contribution

It proposes hierarchical beamforming codebooks, analyzes Doppler effects, and discusses adaptive UAV cruising and positioning strategies for mmWave UAV cellular networks.

Findings

Hierarchical beamforming codebooks improve training speed.

High gain directional transmission mitigates Doppler effects.

Adaptive cruising algorithms help overcome signal blockage.

Abstract

To support high data rate urgent or ad hoc communications, we consider mmWave UAV cellular networks and the associated challenges and solutions. To enable fast beamforming training and tracking, we first investigate a hierarchical structure of beamforming codebooks and design of hierarchical codebooks with different beam widths via the sub-array techniques. We next examine the Doppler effect as a result of UAV movement and find that the Doppler effect may not be catastrophic when high gain directional transmission is used. We further explore the use of millimeter wave spatial division multiple access and demonstrate its clear advantage in improving the cellular network capacity. We also explore different ways of dealing with signal blockage and point out that possible adaptive UAV cruising algorithms would be necessary to counteract signal blockage. Finally, we identify a close relationship between UAV positioning and directional millimeter wave user discovery, where update of the former may directly impact the latter and vice versa.