Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 31 for “"Secondary user"”.
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Dynamic Spectrum Access Network Simulation and Classification of Secondary User Properties
… of determining high-level information about secondary users in a Dynamic Spectrum Access (DSA) network using a low complexity channel sensing method. With a growing number of users generating an increased demand for broadband access, determining an efficient method for utilizing the limited …
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Spectrum-efficient Cooperation and Bargaining-based Resource Allocation for Secondary Users in Cognitive Radio Networks
… by enabling cooperative communication in the secondary networks. We investigate the ability of a two-hop cooperative transmission to reduce the effect of primary user interruption on secondary transmissions. We analyze the performance of a cooperative secondary transmission by modeling the …
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Effect of Doppler shift on adaptive OFDM modulation for cognitive radio application
… on performance. Finally, we consider a two-user CR scenario and investigate the performance effect on a primary user by a secondary user in terms of various Doppler shift offsets where both the primary user and secondary user use OFDM modulations.
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Spectrum sharing in cognitive radio networks
… Cognitive radio enables the unlicensed (secondary) user to establish a communication link in licensed spectrum on the condition that there is no or minimal interference to the licensee (primary user). In this thesis, the two main facets of spectrum sharing in cognitive radio networks are …
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Android Phone Controlled Beagle Board Based PSCR in a Dynamic Spectrum Access Environment
… finds during the scan procedure. It also offers users the capability to scan/classify both analog and digital waveforms. The current PSCR architecture can only run on a general purpose processor and hence is not deployable to the public safety personnel. In the first part of this thesis an …
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Mechanisms for Enhancing Spectrum Utilization in a Spectrum Access System
… to a spectrum sharing system with primary users and secondary users. The spectrum sharing area is modeled as an array of transmit and receive antennas, with the transmit power constraint defined as a function of the interference threshold of the primary user. The area covered by a database …
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Optimization of Spectrum Allocation in Cognitive Radio and Dynamic Spectrum Access Networks
… the primary license holders (also called primary users) remain relatively unused or under-utilized for most of the time. Allowing other users (also called secondary users) without a license to operate in these bands with no interference becomes a promising way to satisfy the fast growing needs for …
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Learning-based adaptive design for dynamic spectrum access in cognitive radio networks.
… which maximize the total throughput of the secondary users in a cognitive radio network. As the first approach, we consider the auction-based formulation in design of dynamic spectrum access mechanisms where it is assumed that primary channels are heterogeneous with distinct availability …
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Resource management of cognitive radio networks with optimization methods.
… so that the induced interference to the licensed user is regulated. The dissertation focuses on solving three kinds of problems of the cognitive radio networks: (1) Multiple-input and multiple-output (MIMO) transmission of cognitive radio networks; (2) Joint reduction of the out-of-band power …
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Spectrum sensing, spectrum monitoring, and security in cognitive radios
… and is used to determine whether a primary user is present in the channel or not. In this dissertation, we formulate and solve the generalized likelihood ratio test (GLRT) for spectrum sensing when both primary user transmitter and the secondary user receiver are equipped with multiple …
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Improvements to Enhance The Security and Reliability of Crowdsourced Spectrum Access Systems and Cognitive Radio Networks
… contributions that follow. To enhance trust in user-reported data, the Whisper Key Location Verification method is introduced. It validates the physical location of crowdsourced nodes by combining radio and internet-based checks, filtering out falsified reports and improving Primary User (PU) …
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Binary consensus-based cooperative spectrum sensing in cognitive radio networks
… to propose a weighted approach in which each secondary user utilizes a set of weights to account for different local sensing qualities of its neighbors as well as different communication link qualities from them. We mathematically characterize the optimum weights. Finally, the impact of …
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Resource Allocation for Interference Management in Wireless Networks
… such as the interference created by legacy users(e.g., primary user transmitters in a cognitive radio network) at non-legacy or unlicensed users(e.g.,secondary user receivers), two mitigation techniques are presented in this dissertation. One exploits permutation trellis codes combined with …
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PERFORMANCE OF COUNTING RULES FOR PRIMARY USER DETECTION
… consider the problem of cooperative sensing for secondary user access to primary user spectrum in cognitive radio systems. Using a fusion center or an access point, the cooperative users decide on the availability of spectrum for their use. Both Neyman-Pearson and Bayes criterion are considered …
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Incorporating Obfuscation Techniques in Privacy Preserving Database-Driven Dynamic Spectrum Access Systems
… presents privacy risks, as sensitive Incumbent User (IU) operation parameters are required to be stored by SAS in order to perform spectrum assignments properly. These sensitive operation parameters may potentially be compromised if SAS is the target of a cyber attack or an inference attack …
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Design and implementation of real-time cognitive dynamic spectrum radio, targeting the FM radio band with PHYDYAS FS-FBMC
… from within MATLAB and Simulink.;The FBMC Secondary User (SU) radio was shown to cause minimal interference to FM Radio stations when 'transmitting' at low broadcast powers (e.g. 20 dBm) and using a 200 kHz guardband, indicating that an SU such as the one proposed in this thesis would be …
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Performance analysis of FBMC over OFDM in Cognitive Radio Network
… can intuitively adjust its parameters to meet users or network demands. The major objective of CR is to provide a platform for the Secondary User (SU) to fully utilize the available spectrum resource by sensing the existence of spectrum holes without causing interference to the Primary User …
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DESIGN AND ANALYSIS OF COGNITIVE MASSIVE MIMO NETWORKS WITH UNDERLAY SPECTRUM SHARING
… also to alleviating propagation losses and inter-user/inter-cell interference. Therefore, massive MIMO has been identified as one of the key candidate technologies for the 5th generation wireless standard. This dissertation thus focuses on (1) developing a performance analysis framework for …
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Relay Selection Strategies for Multi-hop Cooperative Networks
… a constraint on the interference to the primary user. The outage probability of the secondary user and the interference probability at the primary user are analyzed under imperfect CSI scenario. Finally we introduce a hop-by-hop relay selection strategy for underlay spectrum sharing multi-hop …
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Energy-detection based spectrum sensing for cognitive radio on a real-time SDR platform
… spectrum is vacant during times when the primary user is not using the spectrum. This strain on the current available bandwidth has revealed signs of an upcoming spectrum crunch; hence the need to find a solution that satisfies the increasing spectrum demand, without compromising the performance …
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