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.
Results
Showing 1 to 20 of 8057 for “"spectrum"”.
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Spectrum Auctions for Dynamic Spectrum Access Networks
… an auction-based market mechanism for dynamic spectrum sharing when there are multiple sellers and multiple buyers. We assume that the sellers are selfish players and focus on an optimal auction mechanism that maximizes the expected payoff or profit of the seller. First, we study the …
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Spectrum Efficiency and Security in Dynamic Spectrum Sharing
… major paradigm shift in how we manage the radio spectrum. This paradigm shift in spectrum management from exclusive access to shared access is necessitated by the growth of wireless services and the demand pressure imposed on limited spectrum resources under legacy management regimes. The primary …
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Spectrum sensing, spectrum monitoring, and security in cognitive radios
Spectrum sensing is a key function of 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 …
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Spectrum aggregation for dynamic spectrum access based cognitive networks
… distributed in a given area with a fragmented spectrum remains a challenging task. This thesis contributes to the global efforts by extending bandwidth by means of Spectrum Aggregation (SA) in Next Generation Mobile Networks (NGMN). First of all, the motivation behind SA for NGMN is …
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Mechanisms for Enhancing Spectrum Utilization in a Spectrum Access System
… In this thesis, we extend these concepts 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 …
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Spectrum Management Issues in Centralized and Distributed Dynamic Spectrum Access
Dynamic spectrum access (DSA) is a powerful approach to mitigate the spectrum scarcity problem caused by rapid increase in wireless communication demands. Based on architecture design, DSA systems can be categorized as centralized and distributed. To successfully enable DSA, both centralized and …
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Spectrum Management in Dynamic Spectrum Access: A Deep Reinforcement Learning Approach
Dynamic spectrum access (DSA) is a promising technology to mitigate spectrum shortage and improve spectrum utilization. However, DSA users have to face two fundamental issues, interference coordination between DSA users and protections to primary users (PUs). These two issues are very challenging, …
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Optimization of Spectrum Allocation in Cognitive Radio and Dynamic Spectrum Access Networks
Spectrum has become a treasured commodity. However, many licensed frequency bands exclusively assigned to 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 …
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A Context-Aware Dynamic Spectrum Access System for Spectrum Research and Development
… a demand for the increase in the available radio spectrum for communications. The Federal Communications Commission in the United States allowed for the sharing of the CBRS band (3550-3700 MHz) a few years ago. Since then, research has been done by both industry and academia to identify similar …
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Infrared spectrum of hafnium
The construction and operation of microwave excited hafnium discharge tubes is described.
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Spectrum analysis in seismology
Thesis. (Ph.D.) Massachusetts Institute of Technology. Dept. of Geology and Geophysics, 1954.
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Spectrum Opportunity Duration Assurance: A Primary-Secondary Cooperation Approach for Spectrum Sharing Systems
The radio spectrum dependent applications are facing a huge scarcity of the resource. To address this issue, future wireless systems require new wireless network architectures and new approaches to spectrum management. Spectrum sharing has emerged as a promising solution to address the radio …
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Spectrum monitor for cognitive radio
… the activity level across a large range of spectrum in order to assign a channel for its use. Hence a key function is a spectrum monitor to detect the spectrum availability as a first step. This thesis explores the requirements and design issues for the spectrum monitor receiver. The main …
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Distributed spectrum leasing via cooperation
… of secondary activity to perform effective spectrum sensing and on the stringent constraints on protocols and architectures. To address the problems highlighted above, the framework of distributed spectrum leasing via cross-layer cooperation (DiSC) has been recently proposed as a basic …
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Wayfinding in autism spectrum disorders
This study featured the use of ... a comprehensive battery [of tests], designed to assess general spatial ability as well as varieties of spatial cognition (including spatial navigation).
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Spectrum shaping and its application: spread-spectrum clock generator and circuits for ultra wide band
Electromagnetic spectrum can be identified as a resource for the designer, as well as for the manufacturer, from two complementary points of view: first, because it is a good in great demand by many different kind of applications; second, because despite its scarce availability, it may be …
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