Zobrazeno 1 - 10
of 108
pro vyhledávání: '"D.G. Sweeney"'
Autor:
Brian D. Woerner, C. Thompson, G.E. Morgan, C.W. Bostian, Luiz A. DaSilva, Jeffrey H. Reed, W.G. Newhall, D.G. Sweeney, Scott F. Midkiff
Publikováno v:
IEEE Communications Magazine. 44:48-55
Push-to-talk (PTT) technologies date back to the advent of the telegraph and more recently have been the domain of traditional land mobile radio (LMR) networks. The past few years have brought about a resurgence in PTT as a service offered by commerc
Publikováno v:
IEEE Transactions on Antennas and Propagation. 52:3173-3179
In this study we investigated the Local Multipoint Distribution Service band (28 GHz) rough surface scattering properties of limestone and brick walls. Our ultimate goal is to understand the characteristics of radio paths that involve one or more bou
Publikováno v:
IEEE Transactions on Consumer Electronics. 50:856-863
With both Bluetooth and microwave ovens operating in the same frequency band, fears have arisen about the effects of microwave oven interference on Bluetooth networks. While Bluetooth devices use frequency hopping spread spectrum (FHSS), the high pow
Autor:
Charles W. Bostian, D.G. Sweeney
Publikováno v:
IEEE Transactions on Antennas and Propagation. 47:40-46
Satellite systems in the 30/20-GHz band are very susceptible to outages due to rain-induced fades. In order to reduce the impact of these fades, it has been proposed that the power of a transmitting ground station be adjusted during the fade to compe
Autor:
D.G. Sweeney, C.W. Bostian
Publikováno v:
IEEE Transactions on Antennas and Propagation. 40:275-278
The dynamics of rain-induced fades on radio links is studied by evaluating the rate at which the first Fresnel zone volume fills with rain. The amount of water in this volume determines the fade depth, and the rate at which it fills establishes the f
Autor:
D.G. Sweeney, Jeffrey H. Reed
Publikováno v:
Proceedings IEEE SOUTHEASTCON '97. 'Engineering the New Century'.
Autor:
D.G. Sweeney, J.C. McKeeman
Publikováno v:
[Proceedings] GLOBECOM '90: IEEE Global Telecommunications Conference and Exhibition.
The design of a hybrid analog/digital receiver developed to acquire and monitor the Olympus satellite beacons is presented. The analog portion of this receiver uses a frequency-locked loop for signal tracking. A digital sampling detector operating at
Publikováno v:
RAWCON 2000. 2000 IEEE Radio and Wireless Conference (Cat. No.00EX404).
Virginia Tech is involved in both smart base station and smart terminal antenna research for wireless applications. Smart features vary from simple diversity combining to adaptive algorithm implementations. Measurement campaigns are described and res
Publikováno v:
Vehicular Technology Conference Fall 2000. IEEE VTS Fall VTC2000. 52nd Vehicular Technology Conference (Cat. No.00CH37152).
This paper presents results and performance comparisons from indoor and outdoor measurements of space, polarization, and angle diversity for a cellular base station operating in urban environments. The relative performances of the three diversity sch
Publikováno v:
IEEE Antennas and Propagation Society International Symposium. Transmitting Waves of Progress to the Next Millennium. 2000 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.00CH37118).
Cellular telephone systems offer high reliability in favorable environments such as open rural areas. However, in urban areas and in rough terrain mobile and personal terminals experience multipath fading. Diversity techniques are used at the base st