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dc.contributor.authorMaher, Vanessa Rianen_US
dc.date.accessioned2014-03-14T20:38:11Z
dc.date.available2014-03-14T20:38:11Z
dc.date.issued2006-04-28en_US
dc.identifier.otheretd-05222006-190658en_US
dc.identifier.urihttp://hdl.handle.net/10919/33116
dc.description.abstractMany industries are turning to wireless communication systems to track their assets. One example of such an industry is the shipping industry, where â under the growing emphasis on homeland security â tracking cargo containers and their contents has become a high priority. There are several beacons on the commercial market that will meet this need if the required beacon does not need to be independently powered or to have global coverage. This thesis attempts to find a design solution for a beacon that transmits location data, is battery powered, and has world-wide coverage. The beacon is intended to be a low power, transmit only device, and the receiver will not be designed to operate in real-time. Several communication systems were evaluated on these conditions, and the Globalstar Satellite System was selected to use as the communication system for the beacon. The Globalstar Satellite System is a low earth orbiting (LEO) satellite system and uses Code Division Multiple Access (CDMA) to allocate system resources to the maximum number of users possible. Discussions of spread spectrum techniques and theory, Rake receivers, and error correction codes are included as a background for the design. This thesis examines the initial steps in the design of the transmitter beacon and aims to determine the minimum required beacon transmit power for good receiver performance. A portion of the correlator in the Globalstar receiver is simulated for several scenarios: a single user case with varying transmit power, and a multiple user case with fixed transmit power. Although not likely to occur, the single user case was used to baseline system performance and to verify the multi-user case results. The simulated correlator employed a parallel search strategy and used a truncated version of the Globalstar system code sequence. Finally, a threshold analysis was performed to determine if better receiver performance could be obtained.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartfrontmatter.pdfen_US
dc.relation.haspartVRM_ETD.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectspread spectrumen_US
dc.subjectGlobalstaren_US
dc.subjectsatelliteen_US
dc.subjectsimulationen_US
dc.subjectMATLABen_US
dc.subjectCDMAen_US
dc.titleA Low Power Beacon for Transmitting Location Data via the Globalstar Satellite Systemen_US
dc.typeThesisen_US
dc.contributor.departmentElectrical and Computer Engineeringen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineElectrical and Computer Engineeringen_US
dc.contributor.committeechairPratt, Timothy J.en_US
dc.contributor.committeememberBell, Amy E.en_US
dc.contributor.committeememberBuehrer, Richard Michaelen_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-05222006-190658/en_US
dc.date.sdate2006-05-22en_US
dc.date.rdate2006-08-31
dc.date.adate2006-08-31en_US


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