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AuthorKnabe, Fredericdc.contributor.author
Date of accession2016-03-15T09:04:00Zdc.date.accessioned
Available in OPARU since2016-03-15T09:04:00Zdc.date.available
Year of creation2013dc.date.created
AbstractThe use of multiple input multiple output systems as well as the use of relays are without any doubt key elements of future wireless networks. Both techniques ensure high data rates and wide-range coverage. Due to the variety of possibilities for data and signal processing, especially in case of multiple users, the transmit strategies that achieve optimal rates are mostly unknown. In this thesis, we aim for finding transmit strategies that achieve at least near-optimal rates in multi-user channels with an amplify-and-forward relay. The channel models that we consider are the multiple-access relay channel as well as the broadcast relay channel. Moreover, we compare a time division multiple-access (TDMA)-based transmit scheme to a strategy where all stations use the channel at the same time (referred to as joint relaying). In a first step, we neglect the direct links between the transmitter(s) and the receiver(s) and derive the optimal sum-rates of TDMA and joint relaying for the multiple-access relay channel. Moreover, we show that TDMA achieves higher sum-rates than joint relaying. For the broadcast relay channel we derive a heuristic scheme. This scheme has a lower complexity than prevailing schemes and achieves approximately the same rates. Subsequently, we generalize the model by considering also the direct links between the transmitters and the receiver. For this generalization, we find upper and lower bounds on the sum-rate both for TDMA and joint relaying. It turns out that the superiority of TDMA persists for weak direct links but gets lost quickly if the direct links become stronger. Finally, we consider the use of finite alphabets in very noisy broadcast channels, where it can be shown that the optimal performance of Gaussian alphabets is also achieved by quadrature phase shift keying. As a consequence of this, the suboptimality of TDMA at low signal-to-noise ratio, which was already shown for Gaussian alphabets, persists if finite alphabets are used.dc.description.abstract
Languageendc.language.iso
PublisherUniversität Ulmdc.publisher
LicenseStandarddc.rights
Link to license texthttps://oparu.uni-ulm.de/xmlui/license_v3dc.rights.uri
KeywordAmplify-and-Forwarddc.subject
KeywordBroadcastdc.subject
KeywordRelaydc.subject
Dewey Decimal GroupDDC 620 / Engineering & allied operationsdc.subject.ddc
LCSHMIMO systemsdc.subject.lcsh
LCSHMultiple access protocolsdc.subject.lcsh
LCSHTime division multiple accessdc.subject.lcsh
LCSHWireless communication systemsdc.subject.lcsh
TitleTransmit strategies for MIMO multi-user channels with AF-relaydc.title
Resource typeDissertationdc.type
DOIhttp://dx.doi.org/10.18725/OPARU-2531dc.identifier.doi
PPN780646703dc.identifier.ppn
URNhttp://nbn-resolving.de/urn:nbn:de:bsz:289-vts-89252dc.identifier.urn
GNDFunkübertragungdc.subject.gnd
GNDMIMOdc.subject.gnd
GNDTDMAdc.subject.gnd
FacultyFakultät für Ingenieurwissenschaften und Informatikuulm.affiliationGeneral
Date of activation2014-03-11T09:05:58Zuulm.freischaltungVTS
Peer reviewneinuulm.peerReview
Shelfmark print versionW: W-H 13.534uulm.shelfmark
DCMI TypeTextuulm.typeDCMI
VTS-ID8925uulm.vtsID
CategoryPublikationenuulm.category
University Bibliographyjauulm.unibibliographie


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