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Full-Text Articles in Computer Engineering
Coexistence And Secure Communication In Wireless Networks, Saygin Bakşi
Coexistence And Secure Communication In Wireless Networks, Saygin Bakşi
Electrical & Computer Engineering Theses & Dissertations
In a wireless system, transmitted electromagnetic waves can propagate in all directions and can be received by other users in the system. The signals received by unintended receivers pose two problems; increased interference causing lower system throughput or successful decoding of the information which removes secrecy of the communication. Radio frequency spectrum is a scarce resource and it is allocated by technologies already in use. As a result, many communication systems use the spectrum opportunistically whenever it is available in cognitive radio setting or use unlicensed bands. Hence, efficient use of spectrum by sharing users is crucial to increase maximize …
Transparent Spectrum Co-Access In Cognitive Radio Networks, Jonathan Daniel Backens
Transparent Spectrum Co-Access In Cognitive Radio Networks, Jonathan Daniel Backens
Electrical & Computer Engineering Theses & Dissertations
The licensed wireless spectrum is currently under-utilized by as much as 85%. Cognitive radio networks have been proposed to employ dynamic spectrum access to share this under-utilized spectrum between licensed primary user transmissions and unlicensed secondary user transmissions. Current secondary user opportunistic spectrum access methods, however, remain limited in their ability to provide enough incentive to convince primary users to share the licensed spectrum, and they rely on primary user absence to guarantee secondary user performance. These challenges are addressed by developing a Dynamic Spectrum Co-Access Architecture (DSCA) that allows secondary user transmissions to co-access transparently and concurrently with primary …
Smart Sensing And Performance Analysis For Cognitive Radio Networks, Yanxiao Zhao
Smart Sensing And Performance Analysis For Cognitive Radio Networks, Yanxiao Zhao
Electrical & Computer Engineering Theses & Dissertations
Static spectrum access policy has resulted in spectrum scarcity as well as low spectrum utility in today's wireless communications. To utilize the limited spectrum more efficiently, cognitive radio networks have been considered a promising paradigm for future network. Due to the unique features of cognitive radio technology, cognitive radio networks not only raise new challenges, but also bring several fundamental problems back to the focus of researchers. So far, a number of problems in cognitive radio networks have remained unsolved over the past decade. The work presented in this dissertation attempts to fill some of the gaps in the research …