Sun, 27 Jul 2008 07:44:18 BST CiteULike: dcastro's Edwards http://www.citeulike.org/user/dcastro/author/Edwards CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dcastro/article/2877931 <i>Proceedings of the IEEE, Vol. 82, No. 4. (1994), pp. 572-584.</i><br /><br />Only recently has our technology advanced to the point that commercial application of spread-spectrum signaling is economically feasible. This has motivated a number of companies and individuals to seek new ways to benefit from spread-spectrum techniques in commercial systems and products. In this paper, we give a very brief overview of spread spectrum signaling. We then consider applications to satellite mobile applications as well as indoor wireless applications. An overview is presented of several proposals to provide worldwide personal communications through satellite-based spread-spectrum systems, the tradeoffs to be considered, and the controversies involved. A description of a high-capacity wireless office telephone system serves to illustrate how spread-spectrum signaling may be useful in this environment. Finally, we describe a number of digital processing algorithms and devices that implement spread spectrum signaling in a cost-effective manner Spread-spectrum technology for commercial applications DT Magill FD Natali GP Edwards doi:10.1109/5.282243 Proceedings of the IEEE, Vol. 82, No. 4. (1994), pp. 572-584. 2008-06-09T19:24:36-00:00 1994 Proceedings of the IEEE 82 4 572 584 spread-spectrum http://www.citeulike.org/user/dcastro/article/2648158 <i>Acta Astronautica, Vol. 52, No. 2-6. ( 2003), pp. 227-235.</i><br /><br />Mars is the first planet where significant steps are being taken to establish a "virtual presence throughout the solar system"--one of NASA's strategic goals. Preparations are under way to begin implementation of an evolving Mars Network of satellites to meet the future communications and navigation challenges of the ongoing international Mars exploration campaign. The Mars Network concept is to deploy two classes of satellites. The first class is very low-cost MicroSats, launched piggyback on Ariane 5, for deployment in 800-km circular orbits in a variety of planes for frequent global contacts. From their low orbits, the MicroSats provide highly efficient relay communication links for small, energy constrained landers, and their orbital motion provides strong navigation signatures. The second, larger class of Mars areostationary satellites (MARSats) are deployed in 17,000-km orbits with 1-sol periods, as required, to support very high bandwidth users. Mars network for enabling low-cost missions RC Hastrup DJ Bell RJ Cesarone CD Edwards TA Ely JR Guinn SN Rosell JM Srinivasan SA Townes doi:10.1016/S0094-5765(02)00161-3 Acta Astronautica, Vol. 52, No. 2-6. ( 2003), pp. 227-235. 2008-04-10T06:46:39-00:00 2003 Acta Astronautica 52 2-6 227 235 cost low mars network plancom http://www.citeulike.org/user/dcastro/article/2648124 <i>Aerospace Conference, 2005 IEEE (2005), pp. 1266-1285.</i><br /><br />The National Aeronautics and Space Administration (NASA) Exploration Systems Mission Directorate is planning a series of human and robotic missions to the Earth's Moon and to Mars. These missions will require telecommunication and navigation services. This paper sets forth presumed requirements for such services and presents strawman lunar and Mars telecommunications network architectures to satisfy the presumed requirements. The paper suggests that a modest ground network would suffice for missions to the near-side of the Moon. A constellation of three Lunar Telecommunications Orbiters connected to a modest ground network could provide continuous redundant links to a polar lunar base and its vicinity. For human and robotic missions to Mars, a pair of areostationary satellites could provide continuous redundant links between a mid-latitude Mars base and Deep Space Network antennas augmented by large arrays of 12-m antennas. Integrated network architecture for sustained human and robotic exploration GK Noreen RJ Cesarone LJ Deutsch CD Edwards JA Soloff T Ely BM Cook DD Morabito H Hemmati H Hemmati S Piazzolla A10 R Hastrup A11 DS Abraham A12 MK Sue A13 F Manshadi A14 doi:10.1109/AERO.2005.1559417 Aerospace Conference, 2005 IEEE (2005), pp. 1266-1285. 2008-04-10T06:29:59-00:00 2005 Aerospace Conference, 2005 IEEE 1266 1285 architecture integrated mars network plancom http://www.citeulike.org/user/dcastro/article/2421597 <i>Vehicular Technology, IEEE Transactions on, Vol. 39, No. 1. (1990), pp. 56-67.</i><br /><br />The problem of meeting the proliferating demands for mobile telephony within the confinement of the limited radio spectrum allocated to these services is addressed. A multiple-beam adaptive base-station antenna is proposed as a major system component in an attempt to solve this problem. The approach is demonstrated by employing an antenna array capable of resolving the angular distribution of the mobile users as seen at the base-station site, and then using this information to direct beams toward either lone mobiles, or groupings of mobiles, for both transmit and receive modes of operation. The energy associated with each mobile is thus confined within the addressed volume, greatly reducing the amount of cochannel interference experienced from and by neighboring cochannel cells. To ascertain the benefits of such an antenna, the conventional and proposed antenna systems are modeled in a typical mobile radio environment. For a given performance criterion, the theoretical results indicate that a significant increase in the spectral efficiency, or capacity, of the network is obtainable with the proposed antenna The performance enhancement of multibeam adaptive base-station antennas for cellular land mobile radio systems SC Swales MA Beach DJ Edwards JP Mcgeehan doi:10.1109/25.54956 Vehicular Technology, IEEE Transactions on, Vol. 39, No. 1. (1990), pp. 56-67. 2008-02-24T13:46:17-00:00 1990 Vehicular Technology, IEEE Transactions on 39 1 56 67 adaptive antenna beam beamformer cellular mobile multi radio wireless http://www.citeulike.org/user/dcastro/article/1988313 <i>Applied Superconductivity, IEEE Transactions on, Vol. 9, No. 2. (1999), pp. 3889-3892.</i><br /><br />A 2.4 GHz three-stage microstrip bandpass filter was designed using a miniaturized interdigital capacitor structure to reduce the configuration in size. The filter was simulated by a finite element method software and then fabricated using TBCCO superconducting films on 20 mm×20 mm×0.5 mm MgO substrates. It was generated by photolithographic and wet etching process and packaged in a brass box. The bandwidth is 4% and the passband insertion loss of the filter was measured to be -0.4 dB at 77 K. The return loss is better than -8 dB. In particular, this filter has a sharper performance at its edge of fundamental pass band A miniaturized interdigital microstrip bandpass filter Kao-Cheng Huang D Hyland A Jenkins D Edwards D Dew-Hughes Applied Superconductivity, IEEE Transactions on, Vol. 9, No. 2. (1999), pp. 3889-3892. 2007-11-26T20:31:03-00:00 1999 Applied Superconductivity, IEEE Transactions on 9 2 3889 3892 filter interdigital microstrip http://www.citeulike.org/user/dcastro/article/1902913 <i>International Journal of Satellite Communications and Networking, Vol. 25, No. 2. (2007), pp. 111-145.</i><br /><br />Telecommunication is an essential and challenging aspect of planetary exploration. For Mars landers, the constraints of mass, volume, power and energy typically limit their communications capabilities on the long-distance link back to Earth. By deploying relay spacecraft in Martian orbit, these landers can achieve much greater data return and can obtain contact opportunities at times when Earth is not in view. Currently, both NASA and European Space Agency (ESA) have pursued this strategy, deploying relay payloads on their Mars science orbiters. This relay infrastructure has significantly benefited the science return from the 2003 Mars Exploration Rovers and is poised to support the Phoenix Lander and Mars Science Laboratory missions later this decade. Longer-term plans call for continued growth in relay capability, greatly increasing data return from the Martian surface to enable exciting new Mars exploration concepts and advance our understanding of our planetary neighbour. Copyright © 2007 John Wiley & Sons, Ltd. Relay communications for Mars exploration Charles Edwards doi:10.1002/sat.871 International Journal of Satellite Communications and Networking, Vol. 25, No. 2. (2007), pp. 111-145. 2007-11-12T14:13:35-00:00 2007 International Journal of Satellite Communications and Networking 25 2 111 145 communications exploration mars