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dc.contributor.authorKumar, Nishanten_US
dc.date.accessioned2011-08-06T16:01:33Z
dc.date.available2011-08-06T16:01:33Z
dc.date.issued2004-05-04en_US
dc.identifier.otheretd-05172004-123657en_US
dc.identifier.urihttp://hdl.handle.net/10919/9934
dc.description.abstractUltra-Wideband has recently gained great interest for high-speed short-range communications (e.g. home networking applications) as well as low-speed long-range communications (e.g. sensor network applications). Two flavors of UWB have recently emerged as strong contenders for the technology. One is based on Impulse Radio techniques extended to direct sequence spread spectrum. The other technique is based on Orthogonal Frequency Division Multiplexing. Both schemes are analyzed in this thesis and modifications are proposed to increase the performance of each system. For both schemes, the issue of simultaneously operating users has been investigated. Current MAC design for UWB has relied heavily on existing MAC architectures in order to maintain backward compatibility. It remains to be seen if the existing MACs adequately support the UWB PHY (Physical) layer for the applications envisioned for UWB. Thus, in this work we propose a new MAC scheme for an Impulse Radio based UWB PHY, which is based on a CDMA approach using a code-broker in a piconet architecture. The performance of the proposed scheme is compared with the traditional CSMA scheme as well as the receiver-based code assignment scheme. A new scheme is proposed to increase the overall performance of the Multiband-OFDM system. Two schemes proposed to increase the performance of the system in the presence of simultaneously operating piconets (namely Half Pulse Repetition Frequency and Time spreading) are studied. The advantages/disadvantages of both of the schemes are discussed.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.relation.haspartThesis_NishantKumar.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.subjectImpulse Radioen_US
dc.subjectUltra-Widebanden_US
dc.subjectMultiband-OFDMen_US
dc.subjectMedium Access Controlen_US
dc.subjectCDMAen_US
dc.subjectCSMAen_US
dc.titleMAC and Physical Layer Design for Ultra-Wideband Communicationsen_US
dc.typeThesisen_US
dc.contributor.departmentElectrical and Computer Engineeringen_US
dc.description.degreeMSen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
dc.contributor.committeechairBuehrer, Richard Michaelen_US
dc.contributor.committeememberSweeney, Dennis G.en_US
dc.contributor.committeememberDaSilva, Luiz A.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-05172004-123657en_US
dc.date.sdate2004-05-17en_US
dc.date.rdate2004-05-25
dc.date.adate2004-05-25en_US


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