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dc.contributor.advisorDuman, Tolga M.en_US
dc.contributor.authorAyhan, Kadiren_US
dc.date.accessioned2016-04-22T08:24:55Z
dc.date.available2016-04-22T08:24:55Z
dc.date.copyright2016-01
dc.date.issued2016-01
dc.date.submitted02-02-2016
dc.identifier.urihttp://hdl.handle.net/11693/28968
dc.descriptionCataloged from PDF version of thesis.en_US
dc.descriptionIncludes bibliographical references (leaves 53-55).en_US
dc.descriptionThesis (M.S.): Bilkent University, Department of Electrical and Electronics Engineering, İhsan Doğramacı Bilkent University, 2016.en_US
dc.description.abstractThe inherent open nature of the transmission medium makes security a challenging issue in wireless networks. Physical layer security, which is an alternative or a complement to the cryptographic approaches, exploits the differences between the physical properties of different channels in order to provide secrecy. The idea is to ensure that the received signal at an eavesdropper is degraded compared to that of the legitimate receiver in some sense which guarantees that the confidential messages cannot be recovered by an unintended receiver. Over the last decade, various researchers have studied fundamental limits of physical layer security under different wiretap channel models, including Gaussian and fading channels, and with different assumptions on the transmitter’s knowledge on the channel state information. In this thesis, we study physical layer security over frequency selective fading channels modelling certain wireless links. Specifically, we investigate optimal and suboptimal power allocation schemes across frequencies with perfect and partial channel state information at the transmitter with the objective of providing secrecy. We demonstrate that frequency selectivity allows for positive secrecy rates even though the eavesdropper’s channel is not a degraded version of the desired user’s channel. We also analyse the impact of user mobility and the resulting time variations in the wireless medium on the achievable secrecy rates. Furthermore, we consider quantized channel state information at the transmitter and evaluate the secrecy rate loss due to limited feedback from the legitimate receiver to the transmitter. Our results reveal that the partial channel state information at the transmitter can still be helpful in providing positive secrecy rates.en_US
dc.description.statementofresponsibilityby Kadir Ayhan.en_US
dc.format.extentx, 55 leaves : charts.en_US
dc.language.isoEnglishen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subjectPhysical layer securityen_US
dc.subjectFrequency selective fading channelsen_US
dc.subjectPower allocationen_US
dc.subjectMobilityen_US
dc.subjectLimited feedback channelen_US
dc.titlePhysical layer security over frequency selective fading channelsen_US
dc.title.alternativeFrekans seçici azalan kanalllarda fiziksel katmanda güvenliken_US
dc.typeThesisen_US
dc.departmentDepartment of Electrical and Electronics Engineeringen_US
dc.publisherBilkent Universityen_US
dc.description.degreeM.S.en_US
dc.identifier.itemidB152724
dc.embargo.release2016-07-30


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