Richard O'Donnell

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Distributed transmit beamforming using an ad-hoc network of 10 RF transmitters was demonstrated using radio nodes developed from off-the-shelf components and modules. A time-slotted protocol allowed carrier phases from each transmitter to be measured at a receiver and fed back to the transmitters where Kalman filters were used to predict the offset phases(More)
This paper describes the first full implementation and evaluation of an area-based tree visualization known as the PieTree. The PieTree was first proposed in papers in 1998 and 2000 but has never been fully implemented and evaluated. Informal evaluation was used to enhance the usability of the PieTree and compare it with the more well-known TreeMap. A(More)
— This paper addresses the use of distributed coherent communication techniques across a wireless network of tactical radios to enable extended-range communications. Conventional tactical communication systems providing multi-kilometer terrestrial ranges utilize large and costly manpack or vehicular-mount radios. In this paper we discuss techniques for(More)
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