7,567 research outputs found

    Investigation of Shadow Matching for GNSS Positioning in Urban Canyons

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    All travel behavior of people in urban areas relies on knowing their position. Obtaining position has become increasingly easier thanks to the vast popularity of ‘smart’ mobile devices. The main and most accurate positioning technique used in these devices is global navigation satellite systems (GNSS). However, the poor performance of GNSS user equipment in urban canyons is a well-known problem and it is particularly inaccurate in the cross-street direction. The accuracy in this direction greatly affects many applications, including vehicle lane identification and high-accuracy pedestrian navigation. Shadow matching is a new technique that helps solve this problem by integrating GNSS constellation geometries and information derived from 3D models of buildings. This study brings the shadow matching principle from a simple mathematical model, through experimental proof of concept, system design and demonstration, algorithm redesign, comprehensive experimental tests, real-time demonstration and feasibility assessment, to a workable positioning solution. In this thesis, GNSS performance in urban canyons is numerically evaluated using 3D models. Then, a generic two-phase 6-step shadow matching system is proposed, implemented and tested against both geodetic and smartphone-grade GNSS receivers. A Bayesian technique-based shadow matching is proposed to account for NLOS and diffracted signal reception. A particle filter is designed to enable multi-epoch kinematic positioning. Finally, shadow matching is adapted and implemented as a mobile application (app), with feasibility assessment conducted. Results from the investigation confirm that conventional ranging-based GNSS is not adequate for reliable urban positioning. The designed shadow matching positioning system is demonstrated complementary to conventional GNSS in improving urban positioning accuracy. Each of the three generations of shadow matching algorithm is demonstrated to provide better positioning performance, supported by comprehensive experiments. In summary, shadow matching has been demonstrated to significantly improve urban positioning accuracy; it shows great potential to revolutionize urban positioning from street level to lane level, and possibly meter level

    Automated tracking of the Florida manatee (Trichechus manatus)

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    The electronic, physical, biological and environmental factors involved in the automated remote tracking of the Florida manatee (Trichechus manatus) are identified. The current status of the manatee as an endangered species is provided. Brief descriptions of existing tracking and position locating systems are presented to identify the state of the art in these fields. An analysis of energy media is conducted to identify those with the highest probability of success for this application. Logistic questions such as the means of attachment and position of any equipment to be placed on the manatee are also investigated. Power sources and manateeborne electronics encapsulation techniques are studied and the results of a compter generated DF network analysis are summarized

    Korkean luotettavuuden verkkohallinteiset laitteiden vÀliset yhteydet

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    Fifth generation cellular networks aim to provide new types of services. Prominent amongst these are industrial automation and vehicle-to-vehicle communications. Such new use cases demand lower latencies and higher reliability along with greater flexibility than current and past generations of cellular technologies allow. Enabling these new service types requires the introduction of device-to-device communications (D2D). This work investigated network-controlled D2D schemes wherein cellular base stations retain control over spectrum usage. D2D nodes assemble into clusters. Each D2D cluster then organises itself as it sees fit within the constraints imposed by the cellular network. A review of proposed D2D control schemes was conducted to identify pertinent interference issues. Measurements were then devised to empirically collect quantitative data on the impact of this interference. Measurements were conducted using a software-defined radio (SDR) platform. An SDR based system was selected to enable a low cost and highly flexible iterative approach to development while still providing the accuracy of real-world measurement. D2D functionality was added to the chosen SDR system with the essential parts of Long Term Evolution Release 8 implemented. Two series of measurements were performed. The first aimed to determine the adjacent channel interference impact of a cellular user being located near a D2D receiver. The second measurement series collected data on the co-channel interference of spectrum re-use between a D2D link and a moving cellular transmitter. Based on these measurements it was determined that D2D communications within a cellular system is feasible. Furthermore, the required frequency of channel state information reporting as a function of node velocity was determined.Viidennen sukupolven solukkoverkoilla pyritÀÀn mahdollistamaan uudentyyppisiÀ palveluja kuten teollisuusautomatiikkaa ja ajoneuvojen vÀlistÀ viestintÀÀ. TÀmÀnkaltaiset uudet kÀyttötarkoitukset vaativat lyhyempien viiveiden ja korkeammat luotettavuuden ohella myös suurempaa joustavuutta kuin minkÀ nykyisen sukupolven matkapuhelinverkkoteknologiat sallivat. EdellÀ mainittujen uusien palvelujen toteuttaminen vaatii suoria laitteiden vÀlisiÀ yhteyksiÀ (engl. D2D). TÀssÀ diplomityössÀ keskityttiin tutkimaan verkkohallinteisia D2D-rakenteita, joissa solukkoverkko hallinnoi spektrin kÀyttöÀ. D2D-pÀÀtteet liittyvÀt yhteen muodostaakseen klustereita, jotka hallinnoivat sisÀistÀ tietoliikennettÀÀn parhaaksi katsomallaan tavalla solukkoverkon asettamien rajoitusten puitteissa. Kirjallisuuskatsauksen avulla selvitettiin aiemmissa tutkimuksissa esitetyille D2D-ratkaisuille yhteiset interferenssiongelmat. NÀiden vaikutusta ja suuruutta tutkittiin mittausten avulla. Mittaukset toteutettiin ohjelmistoradioalustan (engl. SDR) avulla. SDR-pohjaisen jÀrjestelmÀn kÀyttö mahdollisti edullisen ja joustavan tavan kerÀtÀ empiirisiÀ mittaustuloksia. D2D-toiminnallisuus lisÀttiin Long Term Evolution Release 8:n olennaiset ominaisuudet omaavaan alustaan. TÀllÀ alustalla toteutettiin kaksi mittaussarjaa. EnsimmÀisellÀ kerÀttiin tuloksia viereisellÀ kanavalla toimivan matkapuhelimen D2D-vastaanottimelle aiheuttamasta interferenssistÀ nÀiden ollessa toistensa lÀheisyydessÀ. Toisella mittaussarjalla selvitettiin samalla kanavalla toimivan D2D-yhteyden ja liikkuvan matkapuhelimen vÀlistÀ interferenssiÀ. Mittausten perusteella todettiin D2D-toiminnallisuuden lisÀÀmisen solukkoverkkoon olevan mahdollista. LisÀksi laskettiin vaadittava kanavalaadun pÀivitystiheys pÀÀtteiden nopeuden funktiona

    Enhancing wireless communication system performance through modified indoor environments

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    This thesis reports the methods, the deployment strategies and the resulting system performance improvement of in-building environmental modification. With the increasing use of mobile computing devices such as PDAs, laptops, and the expansion of wireless local area networks (WLANs), there is growing interest in increasing productivity and efficiency through enhancing received signal power. This thesis proposes the deployment of waveguides consisting of frequency selective surfaces (FSSs) in indoor wireless environments and investigates their effect on radio wave propagation. The received power of the obstructed (OBS) path is attenuated significantly as compared with that of the line of sight (LOS) path, thereby requiring an additional link budget margin as well as increased battery power drain. In this thesis, the use of an innovative model is also presented to selectively enhance radio propagation in indoor areas under OBS conditions by reflecting the channel radio signals into areas of interest in order to avoid significant propagation loss. An FSS is a surface which exhibits reflection and/or transmission properties as a function of frequency. An FSS with a pass band frequency response was applied to an ordinary or modified wall as a wallpaper to transform the wall into a frequency selective (FS) wall (FS-WALL) or frequency selective modified wall (FS-MWALL). Measurements have shown that the innovative model prototype can enhance 2.4GHz (IEEE 802.11b/g/n) transmissions in addition to the unmodified wall, whereas other radio services, such as cellular telephony at 1.8GHz, have other routes to penetrate or escape. The FSS performance has been examined intensely by both equivalent circuit modelling, simulation, and practical measurements. Factors that influence FSS performance such as the FSS element dimensions, element conductivities, dielectric substrates adjacent to the FSS, and signal incident angles, were investigated. By keeping the elements small and densely packed, a largely angle-insensitive FSS was developed as a promising prototype for FSS wallpaper. Accordingly, the resultant can be modelled by cascading the effects of the FSS wallpaper and the ordinary wall (FSWALL) or modified wall (FS-MWALL). Good agreement between the modelled, simulated, and the measured results was observed. Finally, a small-scale indoor environment has been constructed and measured in a half-wave chamber and free space measurements in order to practically verify this approach and through the usage of the deterministic ray tracing technique. An initial investigation showing that the use of an innovative model can increase capacity in MIMO systems. This can be explained by the presence of strong multipath components which give rise to a low correlated Rayleigh Channel. This research work has linked the fields of antenna design, communication systems, and building architecture

    Investigations of 5G localization with positioning reference signals

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    TDOA is an user-assisted or network-assisted technique, in which the user equipment calculates the time of arrival of precise positioning reference signals conveyed by mobile base stations and provides information about the measured time of arrival estimates in the direction of the position server. Using multilateration grounded on the TDOA measurements of the PRS received from at least three base stations and known location of these base stations, the location server determines the position of the user equipment. Different types of factors are responsible for the positioning accuracy in TDOA method, such as the sample rate, the bandwidth, network deployment, the properties of PRS, signal propagation condition, etc. About 50 meters positioning is good for the 4G/LTE users, whereas 5G requires an accuracy less than a meter for outdoor and indoor users. Noteworthy improvements in positioning accuracy can be achievable with the help of redesigning the PRS in 5G technology. The accuracy for the localization has been studied for different sampling rates along with different algorithms. High accuracy TDOA with 5G positioning reference signal (PRS) for sample rate and bandwidth hasn’t been taken into consideration yet. The key goal of the thesis is to compare and assess the impact of different sampling rates and different bandwidths of PRS on the 5G positioning accuracy. By performing analysis with variable bandwidths of PRS in resource blocks and comparing all the analyses with different bandwidths of PRS in resource blocks, it is undeniable that there is a meaningful decrease in the RMSE and significant growth in the SNR. The higher bandwidth of PRS in resource blocks brings higher SNR while the RMSE of positioning errors also decreases with higher bandwidth. Also, the number of PRS in resource blocks provides lower SNR with higher RMSE values. The analysis with different bandwidths of PRS in resource blocks reveals keeping the RMSE value lower than a meter each time with different statistics is a positivity of the research. The positioning accuracy also analyzed with different sample sizes. With an increased sample size, a decrease in the root mean square error and a crucial increase in the SNR was observed. From this thesis investigation, it is inevitable to accomplish that two different analyses (sample size and bandwidth) done in a different way with the targeted output. A bandwidth of 38.4 MHz and sample size N = 700 required to achieve below 1m accuracy with SNR of 47.04 dB

    Fort Huachuca joint land use study: Arizona Military Regional Compatibility Project

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    tableOfContents: Introduction -- Study area overview -- Review of existing legislation -- Development trends and issues -- Land use compatibility -- Implementation programabstract: The Fort Huachuca JLUS is part of the Arizona Military Regional Compatibility Project, a proactive statewide endeavor to convene the stakeholders around each base--the relevant jurisdictions, base personnel, landowners, and other interested parties--to address land use compatibility issue

    The Role of Transportation in Campus Emergency Planning, MTI Report 08-06

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    In 2005, Hurricane Katrina created the greatest natural disaster in American history. The states of Louisiana, Mississippi and Alabama sustained significant damage, including 31 colleges and universities. Other institutions of higher education, most notably Louisiana State University (LSU), became resources to the disaster area. This is just one of the many examples of disaster impacts on institutions of higher education. The Federal Department of Homeland Security, under Homeland Security Presidential Directive–5, requires all public agencies that want to receive federal preparedness assistance to comply with the National Incident Management System (NIMS), which includes the creation of an Emergency Operations Plan (EOP). Universities, which may be victims or resources during disasters, must write NIMS–compliant emergency plans. While most university emergency plans address public safety and logistics management, few adequately address the transportation aspects of disaster response and recovery. This MTI report describes the value of integrating transportation infrastructure into the campus emergency plan, including planning for helicopter operations. It offers a list of materials that can be used to educate and inform campus leadership on campus emergency impacts, including books about the Katrina response by LSU and Tulane Hospital, contained in the report®s bibliography. It provides a complete set of Emergency Operations Plan checklists and organization charts updated to acknowledge lessons learned from Katrina, 9/11 and other wide–scale emergencies. Campus emergency planners can quickly update their existing emergency management documents by integrating selected annexes and elements, or create new NIMS–compliant plans by adapting the complete set of annexes to their university®s structures
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