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In this paper, we develop a wireless relay network model for an unmanned aircraft (UA) system, where an UA serves as a resilient moving relay among the ground stations with disconnected communication links in the event of disasters. A fixed-wing type is considered as our UA model, since it can operate longer than a rotary-wing UA without recharging battery, but the former can fly only in a circular...
This paper describes the radio propagation characteristics in urban environment for a fixed-wing unmanned aircraft (UA) system. In the Great East-Japan Earthquake in 2011, the even the latest mobile phones became almost unavailable due to the breakdown of base stations, electricity outage, and traffic congestion. In addition, many areas in mountains or islands were isolated due to the damage of roads,...
This paper proposes a virtual MIMO system model for the unmanned aircraft system (UAS) that consists of a small unmanned aircraft (UA) and multiple ground stations (GSs). Since it is difficult to equip a small UA with multiple antennas due to the limitation of its payload, the proposed system exploits a mobility of the single- antenna UA to realize virtual MIMO channels. The channel is assumed to...
Toward increased use of unmanned aircrafts (UA), researches and standardizations of the control communication system for UA using satellites in ITU-R and the like have been discussed recently. The National Institute of Information and Communications Technology (NICT) has been developing an on-board tracking antenna system for UA which realizes a communication link between UA and remote pilot through...
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