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dc.contributor.advisorDuman, Tolga Mete
dc.contributor.authorAghdam, Sina Rezaei
dc.date.accessioned2018-01-11T10:19:32Z
dc.date.available2018-01-11T10:19:32Z
dc.date.copyright2017-12
dc.date.issued2018-01
dc.date.submitted2018-01-10
dc.identifier.urihttp://hdl.handle.net/11693/35734
dc.descriptionCataloged from PDF version of article.en_US
dc.descriptionThesis (Ph.D.): Bilkent University, Department of Electrical and Electronics Engineering, İhsan Doğramacı Bilkent University, 2017.en_US
dc.descriptionIncludes bibliographical references (leaves 116-125).en_US
dc.description.abstractWith the ever-growing demand for services that rely on transmission over wireless networks, a challenging issue is the security of the transmitted information. Due to its open nature, wireless communications is prone to eavesdropping attacks. Typically, secrecy of the transmitted information is ensured with the aid of cryptographic techniques, which are deployed on upper layers of the network protocol stack. However, due to the need for key distribution and management, cryptographic solutions are difficult to implement in decentralized networks. Moreover, the security provided by key based solutions is not provable from a mathematical point of view. Physical layer security is an alternative or complement to the cryptographic techniques, which can resolve the complexities associated with key distribution and management. The basic principle of physical layer security is to exploit the randomness of the communication channels to allow a transmitter deliver its message to an intended receiver reliably while guaranteeing that a third party cannot infer any information about it. Much of the existing research in physical layer security focuses on investigating the information theoretic limits of secure communications. Among different techniques proposed, multiple-antenna based solutions have been shown to exhibit a high potential for enhancing security. Furthermore, Gaussian inputs are proved to be the optimal input distributions in a variety of scenarios. However, due to the high detection complexity, Gaussian signaling is not used in practice, and the transmission is carried out with the aid of symbols drawn from standard signal constellations. In this thesis, we develop several secure multi-antenna transmission techniques under the practical finite-alphabet input assumption. We first consider multipleinput multiple-output (MIMO) wiretap channels under finite-alphabet input constraints. We assume that the statistical channel state information (CSI) of the eavesdropper is available at the transmitter, and study two different scenarios regarding the transmitter's knowledge on the main channel CSI (MCSI) including availability of perfect and statistical MCSI at the transmitter. In each scenario, we introduce iterative algorithms for joint optimization of data precoder and arti ficial noise. We also propose different strategies to reduce the computational complexity associated with the transmit signal design. Moreover, we consider the setups with simultaneous wireless information and power transfer (SWIPT), and propose transmission schemes for achieving the trade-off between the secrecy rate and the harvested power. We demonstrate the efficacy of the proposed transmit signal design algorithms via extensive numerical examples. We also introduce several secure transmission schemes with spatial modulation and space shift keying (SSK). We derive an expression for the achievable secrecy rate, and develop precoder optimization algorithms for its maximization using transmitter side CSI. Furthermore, we introduce a group of secure SSK transmission schemes, which rely on dynamic antenna index assignment over reciprocal channels. Our results reveal that the fundamentally different working principle of SSK opens up new avenues for secure multi-antenna transmission.en_US
dc.description.statementofresponsibilityby Sina Rezaei Aghdam.en_US
dc.format.extentxvi, 133 leaves : charts ; 30 cmen_US
dc.language.isoEnglishen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subjectPhysical layer securityen_US
dc.subjectFinite-alphabet inputsen_US
dc.subjectMIMO communicationsen_US
dc.subjectChannel state informationen_US
dc.subjectPrecodingen_US
dc.subjectArtificial noiseen_US
dc.subjectCut-off rateen_US
dc.subjectSimultaneous wireless information and power transferen_US
dc.subjectSpatial modulationen_US
dc.subjectSpace shift keyingen_US
dc.titleSecure multi-antenna transmission with finite-alphabet signalingen_US
dc.title.alternativeSonlu girdi setine sahip sinyallerle çok antenli güvenli iletimen_US
dc.typeThesisen_US
dc.departmentDepartment of Electrical and Electronics Engineeringen_US
dc.publisherBilkent Universityen_US
dc.description.degreePh.D.en_US
dc.identifier.itemidB157368
dc.embargo.release2018-07-10


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