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 16 of 16 for “"diversity systems"”.
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Synthesis of Optimal Arrays For MIMO and Diversity Systems
… element radiation characteristics which maximize diversity gain given a specific power angular spectrum of the propagation environment. The method numerically constructs the eigenfunctions of the covariance operator for the scenario subject to constraints on the power radiated by each antenna as …
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Performance Evaluation of Equal Gain Diversity Systems In Fading Channels
Next generation wireless systems are being designed to provide ubiquitous broadband link access to information infrastructure. Diversity techniques play a vital role in supporting such high speed connections over radio channels by mitigating the detrimental effects of multiuser interference and …
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Analysis and test of patch antennas for applications in dual-band and diversity systems
… patch antennas for applications in dual-band and diversity systems is presented. The dual-band capability is achieved with two patches that are stacked vertically and coupled by an aperture in the lower patch. The aperture provides a convenient way of adjusting the separation between the resonant …
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Adaptive Relay-Selection In Decode-And-Forward Cooperative Systems
… years adaptive decode-and-forward cooperative diversity systems have been studied intensively in literature. Many schemes and protocols have been proposed to enhance the performance of the cooperative systems while trying to alleviate its drawbacks. One of the recent schemes that had been shown …
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The Direct and Indirect Effects of Insectivory by Birds in Two Neotropical Forests
… and restricted to saplings in relatively low diversity systems. In two lowland tropical forests, I tested whether birds indirectly defend canopy and understory plant foliage from arthropod herbivores. The two forest sites differed in age, tree species diversity and rainfall seasonality. Birds …
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Feedback Communication Systems for Time-Varying Channels
The growing use of centralized data processing systems has led to a demand for data transmission facilities from remote locations, mobile stations, and even from space. To meet this demand the possibilities of data transmission over radio channels have been widely investigated. A major problem …
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Analysis of a Two-Branch Maximal Ratio and Selection Diversity System with Unequal Branch Powers and Correlated Inputs for a Rayleigh Fading Channel
… an analytical framework for analyzing two-branch diversity systems for a Rayleigh fading channel. In many cases the fading received at both branches (i.e. a two-antenna element system) is correlated because of the proximity of the antenna elements to each other. It is also not uncommon for a …
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Measurement System and Campaign for Characterizing the Theoretical Capacity and Cross-Correlation of Multiple-Input Multiple Output Indoor Wireless Channels
… have historically motivated research in spatial diversity systems. Diversity techniques have been implemented in many current systems and have been shown to reduce the transmit power required to maintain acceptable system performance. Traditionally spatial diversity is based on the transmission …
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Evolution of reptile diversity in tropical savannas - a study across scales and continents
What promotes biological diversity? Accurately recognising and describing patterns of diversity is fundamental to understanding the evolutionary and ecological processes underpinning diversification. The history of living organisms is expressed at multiple dimensions, ranging from speciation …
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Evolution of reptile diversity in tropical savannas - a study across scales and continents
What promotes biological diversity? Accurately recognising and describing patterns of diversity is fundamental to understanding the evolutionary and ecological processes underpinning diversification. The history of living organisms is expressed at multiple dimensions, ranging from speciation …
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Design of single-carrier frequency domain equalization (SC-FDE) with transmit diversity for wireless and optical communications
… efficiency and manufacturing cost. Transmit diversity systems, such space-time block coding (STBC) and space- frequency block coding (SFBC) have be proven to increase the performance of wireless system by exploiting the spatial diversity of the channel. In this dissertation, the authors focus …
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Plant root contributions to the carbon balance of a changing agricultural Midwest
… biology, and biogeochemistry. In agricultural systems, C storage is fully determined by belowground pools, so it is vital to understand the links between root placement and C status under a variety of potential future conditions and land use types. I considered three such links: the long-term …
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Control of an indoor autonomous mobile communications relay via antenna diversity
… controller presented here is driven by antenna diversity and attempts to optimize the inputs to an unknown, time-varying cost function characterized by the RF environment. Each of the multiple antennas onboard the quadrotor receives the same incoming packets and provides associated signal …
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Υβριδική στοχαστική-ηλεκτρομαγνητική ανάλυση της λειτουργίας των κεραίων σε συστήματα διαφορισμού λήψης και πολλαπλών εισόδων πολλαπλών εξόδων
Στην παρούσα διδακτορική διατριβή, με βάση την ηλεκτρομαγνητική θεωρία,παρουσιάζεται μία μεθοδολογία για τη μοντελοποίηση πολύθυρων κεραιών κατά την κατάσταση εκπομπής και λήψης τους, δύο στοχαστικές μεθοδολογίες για την αξιολόγησή τους κατά τη λειτουργία τους σε συστήματα διαφορισμού λήψης και μία …
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Advancing Internet Viewpoint Diversity: A Novel Algorithm and a Corpus Creation Tool
… regarding how information technology affects the diversity of viewpoints available. In response to an increasingly polarized society and worries surrounding filter bubbles and algorithmic bias, this research presents a novel tool for constructing internet-based topical corpora and an algorithm …