Understanding UAV cellular communications: from existing networks to massive MIMO

The purpose of this article is to bestow the reader with a timely study of UAV cellular communications, bridging the gap between the 3GPP standardization status quo and the more forward-looking research. Special emphasis is placed on the downlink command and control (C&C) channel to aerial u...

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Detalhes bibliográficos
Autores: Geraci, Giovanni, García Rodríguez, Adrián, Galati Giordano, Lorenzo, López Pérez, David, Björnson, Emil
Tipo de documento: artigo
Estado:Versión aceptada para publicación
Data de publicação:2018
País:España
Recursos:Universitat Pompeu Fabra
Repositório:Repositorio Digital de la UPF
OAI Identifier:oai:repositori.upf.edu:10230/44042
Acesso em linha:http://hdl.handle.net/10230/44042
http://dx.doi.org/10.1109/ACCESS.2018.2876700
Access Level:Acceso aberto
Palavra-chave:Unmanned aerial vehicles
UAVs
Command
Control channel
Cellular networks
Massive MIMO
3GPP
Descrição
Resumo:The purpose of this article is to bestow the reader with a timely study of UAV cellular communications, bridging the gap between the 3GPP standardization status quo and the more forward-looking research. Special emphasis is placed on the downlink command and control (C&C) channel to aerial users, whose reliability is deemed of paramount technological importance for the commercial success of UAV cellular communications. Through a realistic side-by-side comparison of two network deployments – a present-day cellular infrastructure versus a next-generation massive MIMO system – a plurality of key facts are cast light upon, with the three main ones summarized as follows: (i) UAV cell selection is essentially driven by the secondary lobes of a base station’s radiation pattern, causing UAVs to associate to far-flung cells; (ii) over a 10 MHz bandwidth, and for UAV heights of up to 300 m, massive MIMO networks can support 100 kbps C&C channels in 74% of the cases when the uplink pilots for channel estimation are reused among base station sites, and in 96% of the cases without pilot reuse across the network; (iii) supporting UAV C&C channels can considerably affect the performance of ground users on account of severe pilot contamination, unless suitable power control policies are in place.