Dissertations / Theses: 'Wireless communication systems – Data processing'

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Hui, Chui Ying. "Broadcast algorithms and caching strategies for mobile transaction processing." HKBU Institutional Repository, 2007. http://repository.hkbu.edu.hk/etd_ra/781.

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Woon, Thean Hung Wilson, and 云天恒. "Effective distributed broadcasting protocols for wireless networks." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45880190.

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Olson, Chandra. "Jini an investigation in distributed computing /." [Florida] : State University System of Florida, 2001. http://etd.fcla.edu/etd/uf/2001/ank7122/chandra.PDF.

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Thesis (M.E.)--University of Florida, 2001.
Title from first page of PDF file. Document formatted into pages; contains viii, 71 p.; also contains graphics. Vita. Includes bibliographical references (p. 69-70).

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Zheng, Baihua. "Indexing of location-dependent data in mobile computing environments /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?COMP%202003%20ZHENG.

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Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003.
Vita. Includes bibliographical references (leaves 168-180). Also available in electronic version. Access restricted to campus users.

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Gong, Yi. "Space-time coding for high data-rate wireless communications over space and frequency selective fading channels /." View Abstract or Full-Text, 2002. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202002%20GONG.

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Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2002.
Includes bibliographical references (leaves 105-114). Also available in electronic version. Access restricted to campus users.

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Lee, Kelvin Kai-wing. "A delay model approach to analysing the performance of wireless communications /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?COMP%202005%20LEE.

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Saliaris, Ioannis R. "Real-Time data acquisition and processing of the Magnetic, Angular Rate and Gravity (MARG) sensor /." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Jun%5FSaliaris.pdf.

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Thesis (M.S. in Electrical Engineering and M.S. in Systems Engineering)--Naval Postgraduate School, June 2004.
Thesis advisor(s): Xiaoping Yun. Includes bibliographical references (p. 59-60). Also available online.

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Wang, Yinan. "An Implementation of Consensus Through Bluetooth Communication." Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc500099/.

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This thesis provides an implementation of consensus of multi-agent networked systems. Consensus problem is an important issue of distributed computing and has various algorithms and applications in the field of electronical and computer science. The consensus requests all nodes of a network reach an agreement over a certain measurement. An algorithm of convergent consensus problem is implemented through a small network of Bluetooth communication in the thesis. The connections of the Bluetooth devices are wireless, and the device nodes of the network are driven by C++ software and Winsock API. The simulation results show that the implementation completes all the requirements of the distributed consensus algorithm.

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Gurung, Sanjaya. "Integrating environmental data acquisition and low cost Wi-Fi data communication." Thesis, University of North Texas, 2009. https://digital.library.unt.edu/ark:/67531/metadc12131/.

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This thesis describes environmental data collection and transmission from the field to a server using Wi-Fi. Also discussed are components, radio wave propagation, received power calculations, and throughput tests. Measured receive power resulted close to calculated and simulated values. Throughput tests resulted satisfactory. The thesis provides detailed systematic procedures for Wi-Fi radio link setup and techniques to optimize the quality of a radio link.

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Imsuksri, Sumit. "Mobile order entry system based on the wireless technology." CSUSB ScholarWorks, 2002. https://scholarworks.lib.csusb.edu/etd-project/2265.

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The sales representatives primary duties are to attract wholesale and retail buyers and purchasing agents to their merchandise, and to address any of their client's questions or concerns. Aided by a laptop computer connected to the Internet, they can access the customer information and sell products to their customer immediately. This project, a Mobile Order Entry System using cellphones, will give sales representatives as state-of-the-art alternative in accessing anf selling products to their customers through cell phones instead of using laptop computers.

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Raghunathan, Arun Roppel Thaddeus A. "Ad-hoc and multi-hop wireless sensor networks for activity capture in cooperative robotics." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Summer/Theses/RAGHUNATHAN_ARUN_24.pdf.

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Visser, Schalk W. J. (Schalk Willem Jacobus). "Data capturing system using cellular phone, verified against propagation models." Thesis, Stellenbosch : University of Stellenbosch, 2004. http://hdl.handle.net/10019.1/16462.

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Thesis (MScIng)--University of Stellenbosch, 2004.
ENGLISH ABSTRACT: Data capturing equipment are an expensive part of testing the coverage of a deployed or planned wireless service. This thesis presents the development of such a data capturing system that make use of 1800MHz GSM base stations as transmitters and a mobile phone connected to a laptop as receiver. The measurements taken, are then verified against know propagation models. Datavaslegging toerusting wat gebruik word om die dekking van draadlose stelsels te toets is baie duur en moeilik bekombaar. Hierdie tesis beskryf die ontwikkeling van so ’n datavaslegger wat baie goedkoper is en maklik gebruik kan word. Dit maak gebruik van ’n sellulêr foon en GPS gekoppel aan ’n skootrekenaar, wat die ontvanger is. Cell C basis staties word gebruik as die senders. Die data wat gemeet is word dan geverifieer deur gebruik te maak van bestaande radio frekwensie voortplanting modelle.

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Motahari, Bidgoli Seyed Mohammad Amin. "An Optical Design Configuration for Wireless Data Transmission." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2439.

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The concept of 2D barcodes is of great relevance for use in wireless data transmission between handheld electronic devices. In a typical setup, any file on a cell phone for example can be transferred to a second cell phone through a series of images on the LCD which are then captured and decoded through the camera of the second cell phone. In this research, a new approach for data modulation in 2D barcodes is introduced, and its performance is evaluated in comparison to other standard methods of barcode modulation. In the proposed method, Orthogonal Frequency Division Multiplexing (OFDM) modulation is used together with Differential Phase Shift Keying (DPSK) over adjacent frequency domain elements to modulate intensity of individual pixels. It is shown that the bit error rate performance of the proposed system is superior to the current state of the art in various scenarios. A specific aim of this study is to establish a system that is proven tolerant to camera motion, picture blur and light leakage within neighboring pixels of an LCD. Furthermore, intensity modulation requires the input signal used to modulate a light source to be positive, which requires the addition of a dc bias. In the meantime, the high crest factor of OFDM requires a lower modulation index to limit clipping distortion. These two factors result in poor power efficiency in radio over fiber applications in which signal bandwidth is generally much less than the carrier frequency. In this study, it is shown that clipping a bipolar radio frequency signal at zero level, when it has a carrier frequency sufficiently higher than its bandwidth, results in negligible distortion in the pass band and most of the distortion power is concentrated in the baseband. Consequently, with less power provided to the optical carrier, higher power efficiencies and better receiver sensitivity will result. Finally, a more efficient optical integrated system is introduced to implement the proposed intensity modulation method which is optimized for radio over fiber applications.

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Jenkins, William George. "Real-time vehicle performance monitoring with data integrity." Master's thesis, Mississippi State : Mississippi State University, 2006. http://sun.library.msstate.edu/ETD-db/ETD-browse/browse.

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Thurston, Michael J. "A pragmatic view of MANET performance evaluation and design of a prototype MAC level routing algorithm." Link to electronic thesis, 2003. http://www.wpi.edu/Pubs/ETD/Available/etd-0108103-122903.

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Li, Yingjie. "Information dissemination and routing in communication networks." Columbus, Ohio : Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1132767756.

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Zhang, Hongwei. "Dependable messaging in wireless sensor networks." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1155607973.

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Jiang, Jeng-Shiann. "Measurement, Modeling, and Performance, of Indoor MIMO Channels." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5035.

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The objective of this dissertation is to investigate the performance of the recently proposed MIMO technology in real indoor environments based on channel measurements centered at 5.8 GHz. First, a MIMO channel measurement system is implemented based on the virtual antenna array infrastructure. This measurement testbed can acquire the wideband channel matrices of MIMO systems with arbitrary array geometries. The measurement system structure and measurement procedure are described in detail in the first part. The second part is about MIMO channel modeling. Two novel number-of-sources detection algorithms, which are more robust and suitable for practical applications than traditional methods, are proposed. The MIMO path parameters, including delay, DOA, and DOD are estimated from measured data by several estimation schemes based on the ESPRIT algorithm. The accuracies of these estimation schemes are evaluated in terms of the estimation error between the capacities of the directly measured and the reconstructed channels. Moreover, based on ray tracing and measurement results, the spherical wave model is suggested to replace conventional plane wave model in order to prevent the capacity underestimation of short-range MIMO channels. An important observation is that short-range MIMO can achieve full capacity in free space channel. A threshold distance is derived to determine whether the spherical wave model is necessary. In the final part, measurements conducted in the Residential Laboratory are used to investigate the impact of element spacing, LOS, interference, spatial correlation between the interfering and data links, and stream control. A capacity enhancement scheme, which improves the performance by adapting the element locations, is implemented using our measurement system. Finally, the performances of beam selection and antenna selection in combination with MIMO technologies are compared in both narrowband and wideband channels.

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Li, Ling Feng. "An image encryption system based on two-dimensional quantum random walks." Thesis, University of Macau, 2018. http://umaclib3.umac.mo/record=b3950660.

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Butkus, Kazimieras. "Objektų vietos nustatymo technologinių paklaidų įvertinimo sistema." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2008. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20080128_104821-95531.

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Šis darbas tiria objetų vietos nustatymo paklaidų problemą bevieliuose tinkluose ir leidžia jas įvertinti įvairiais aspektais. Įvertinimo rezultatas pateikiamas kaip sugeneruotas geografinis žemėlapis bei tekstinės reikšmės. Sistema sukurta taip, kad nepriklausytų nuo bevielių ryšių technologijos, o duomenų analizės rezulate sistema leidžia juos peržiūrėti valdant geografinę padėtį bei tikslumą. Ši sistema naudojama realiose aplikacijose, pavyzdžiui, MSC MPS R5 LBS, MPS112 platformoje, taip pat „Bitės tinklo padengimo žemėlapiai“ sprendime. Sistemos veikimas yra universalus ir ji gali būti naudojama įvairiose komercinėse tinklų planavimo ar LBS platformose. Sistema nepriklauso nuo bevielės technologijos ypatumų ir bus tinkama naudoti ateities bevielių tinklų įvertinimui.
This work investigates problem of positioning calculation error in mobile cellular networks and provides means to evaluate the errors in variuos aspects. Evaluation results are presented as generated geographical maps and values. The positioning calculation error evaluation is then used to extract requirements for engineered system. System is engineered in a way that it is cellular technology independand and is not limited by generations or carrier technologies of particular investigated networks. Resulting system allows users to select geographical area and precision of analysis to be carried on positioning calculation error. Radio signal propagation and coverage estimation algorithms are used to interpret input data and GIS data is used together to provide visual interpretation for positioning calculation error. This system is beeing used in real word aplications. At the time the system is used in MSC MPS R5 LBS, MPS112 platforms, also in solution „Bitės tinklo padengimo žemėlapiai“. Solution is universal, it can be used in variuos commercial network planning and LBS platforms. The system is cellular network technology neutral and it will be possible to evaluate future cellular or wireless networks as well.

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Kativu, Tatenda Kevin. "A framework for the secure consumerisation of mobile, handheld devices in the healthcare institutional context." Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/18630.

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The advances in communication technologies have resulted in a significant shift in the workplace culture. Mobile computing devices are increasingly becoming an integral part of workplace culture. Mobility has several advantages to the organisation, one such example is the “always online” workforce resulting in increased productivity hours. As a result, organisations are increasingly providing mobile computing devices to the workforce to enable remote productivity at the organisations cost. A challenge associated with mobility is that these devices are likely to connect to a variety of networks, some which may insecure, and because of their smaller form factor and perceived value, are vulnerable to loss and theft amongst other information security challenges. Increased mobility has far reaching benefits for remote and rural communities, particularly in the healthcare domain where health workers are able to provide services to previously inaccessible populations. The adverse economic and infrastructure environment means institution provided devices make up the bulk of the mobile computing devices, and taking away the ownership, the usage patterns and the susceptibility of information to adversity are similar. It is for this reason that this study focuses on information security on institution provided devices in a rural healthcare setting. This study falls into the design science paradigm and is guided by the principles of design science proposed by Hevner et al. The research process incorporates literature reviews focusing on health information systems security and identifying theoretical constructs that support the low-resource based secure deployment of health information technologies. Thereafter, the artifact is developed and evaluated through an implementation case study and expert reviews. The outcomes from the feedback are integrated into the framework.

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Chinpanich, Vorapong. "Helpdesk Support Alert System." CSUSB ScholarWorks, 2004. https://scholarworks.lib.csusb.edu/etd-project/2674.

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The goal of this project was to implement the Helpdesk Support Alert System in the Data Center Services (DCS) of California State University, San Bernardino's (CSUSB's) Information Resource and Technology Division (IRT). DCS is responsible for ensuring uninterrupted operation of all CSUSB administrative computing systems. These responsibilities include user support, system maintenance, and system security. The DCS helpdesk cannot be staffed 24 hours a day; this application is designed to alert DCS technicians of emergencies when they are away from the helpdesk. The Helpdesk Support Alert System sends out an automated emergency alert in the form of a short text message to technicians' mobile phones. Technicians respond back to their main office by using the Wireless Application Protocol (WAP) capability of their mobile phones.

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Merugu, Shashidhar. "Network Design and Routing in Peer-to-Peer and Mobile Ad Hoc Networks." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7219.

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Peer-to-peer networks and mobile ad hoc networks are emerging distributed networks that share several similarities. Fundamental among these similarities is the decentralized role of each participating node to route messages on behalf of other nodes, and thereby, collectively realizing communication between any pair of nodes. Messages are routed on a topology graph that is determined by the peer relationship between nodes. Although routing is fairly straightforward when the topology graph is static, dynamic variations in the peer relationship that often occur in peer-to-peer and mobile ad hoc networks present challenges to routing. In this thesis, we examine the interplay between routing messages and network topology design in two classes of these networks -- unstructured peer-to-peer networks and sparsely-connected mobile ad hoc networks. In unstructured peer-to-peer networks, we add structure to overlay topologies to support file sharing. Specifically, we investigate the advantages of designing overlay topologies with small-world properties to improve (a) search protocol performance and (b) network utilization. We show, using simulation, that "small-world-like" overlay topologies where every node has many close neighbors and few random neighbors exhibit high chances of locating files close to the source of file search query. This improvement in search protocol performance is achieved while decreasing the traffic load on the links in the underlying network. In the context of sparsely-connected mobile ad hoc networks where nodes provide connectivity via mobility, we present a protocol for routing in space and time where the message forwarding decision involves not only where to forward (space), but also when to forward (time). We introduce space-time routing tables and develop methods to compute these routing tables for those instances of ad hoc networks where node mobility is predictable over either a finite horizon or indefinitely due to periodicity in node motion. Furthermore, when the node mobility is unpredictable, we investigate several forwarding heuristics to address the scarcity in transmission opportunities in these sparsely-connected ad hoc networks. In particular, we present the advantages of fragmenting messages and augmenting them with erasure codes to improve the end-to-end message delivery performance.

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Azim, Ali Waqar. "Signal Processing Techniques for Optical Wireless Communication Systems." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAT059/document.

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Le spectre radiofréquence (RF) diminue en raison d'une augmentation de la demande d'applications sans fil. Par conséquent, il existe une demande importante de régions de spectre alternatifs pour les communications afin d'incliner le spectre RF conventionnel. Dans ce contexte, les communications optiques sans fil (OWC) sont explorées comme un candidat potentiel pour compléter les communications RF. Le travail actuel se concentre sur les techniques d'atténuation des déficiences et les approches de modulation efficaces en énergie pour OWC. Dans un premier temps, on étudie le rapport de puissance crête à moyenne (PAPR) pour le multiplexage par répartition orthogonale de la fréquence optique (O-OFDM) et on présente deux techniques de réduction de PAPR orientées vers la décision. La complexité de ces méthodes est comparativement plus faible que celle des autres méthodes de réduction PAPR, tandis que leurs performances sont également analogues à celles des autres alternatives. Deuxièmement, une approche d'accès multiple par répartition en fréquence optique-porteuse unique (O-SCFDMA), appelée O-SCFDMA sans symétrie d'Hermitain (HSFO-SCFDMA) est proposée. Ce dernier évite la symétrie hermiatienne normalement attendue pour d'autres O-OFDM et Approches O-SCFDMA. Les résultats de la simulation affirment que HSFO-SCFDMA est plus efficace que toute autre approche O-SCFDMA pour OWC et manifeste le plus faible PAPR parmi les autres alternatives. Troisièmement, la performance du précodage est analysée pour l'O-OFDM (LACO-OFDM) asymétriquement en couches. Deux types de précodage sont utilisés, à savoir le précodage par transformée de Fourier et le précodage par transformée d'Hartley. Il est établi que le LACO-OFDM précodé a transformée Hartley présente le PAPR le plus faible et est moins vulnérable à la distorsion non linéaire introduite par les diodes électroluminescentes (LED), mais le rapport signale sur bruit (SNR) augmente ( électrique et optique à la fois) en raison de la structure en couches qui est plus élevée que le LACO-OFDM conventionnelle
The radio-frequency (RF) spectrum is dwindling due to an increase in the demand of wireless applications. Hence, there is substantial demand of alternative spectrum regions for communications to recline the conventional RF spectrum. In this context, optical wireless communications (OWC) is explored as a likely candidate to supplement the RF communications. The current work focuses on impairment mitigation techniques and energy-efficient modulation approaches for OWC. Firstly, the peak-to-average power ratio (PAPR) for optical-orthogonal frequency division multiplexing (O-OFDM) is studied and two decision-directed PAPR reduction techniques are presented. The complexity of these methods is comparatively lower than other PAPR reduction methods, whilst, their performance is likewise analogous with other alternatives. Secondly, an optical-single-carrier frequency division multiple access (O-SCFDMA) approach, referred to as Hermitain symmetry free O-SCFDMA (HSFO-SCFDMA) is proposed, that averts Hermiatian symmetry which is normally expected for other O-OFDM and O-SCFDMA approaches. The simulation results affirm that HSFO-SCFDMA is more efficient than any other O-SCFDMA approach for OWC and manifests the lowest PAPR among the other alternatives. Thirdly, the performance of precoding is analyzed for layered asymmetrically clipped O-OFDM (LACO-OFDM). Two types of precoding are employed, i.e., Fourier transform precoding and Hartley transform precoding. It is established that Hartley transform precoded LACO-OFDM exhibits the lowest PAPR and is less vulnerable to non-linear distortion introduced by the light emitting diodes (LEDs), howbeit, the signal-to-noise ratio (SNR) increase (both electrical and optical) owing to the layered structure is higher than conventional LACO-OFDM

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Henao, Roa Yull Heilordt 1978. "Instrumentos dedicados à análise do impacto aplicados à agricultura e ao Esporte." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260398.

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Orientador: Fabiano Fruett
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação
Made available in DSpace on 2018-08-23T18:28:13Z (GMT). No. of bitstreams: 1 HenaoRoa_YullHeilordt_D.pdf: 5648105 bytes, checksum: a3dd3974832587d7000df5c643e2d6d9 (MD5) Previous issue date: 2013
Resumo: Os frutos submetidos a grandes impactos sofrem danos irreversíveis, perdem qualidade e nem sempre podem ser aproveitados no final do processo de pós-colheita. Identificar e entender estes eventos críticos pode colaborar na redução do desperdício na produção de alimentos. Já no caso do esporte, o estudo dos impactos do equipamento esportivo levando em consideração características particulares do material pode ser uma ferramenta valiosa durante o desenvolvimento e fabricação de, por exemplo: bolas de futebol. Com o objetivo de fornecer novas ferramentas à análise e ao estudo dos impactos na agricultura e nos esportes desenvolvemos o hardware e o software de dois instrumentos os quais interagem de forma sincronizada com o método da cinemetria para análise de movimento através de câmeras. O primeiro instrumento desenvolvido é um sistema de monitoramento de variáveis biomecânicas chamado Esfera Eletrônica Sem Fio (EESF). Na agricultura, o circuito eletrônico da EESF, é encapsulado dentro de uma esfera, facilitando o monitoramento de frutas e outros produtos perecíveis mediante a aquisição de variáveis que afetam a qualidade do produto. No esporte, o circuito eletrônico pode ser encapsulado, acoplado ou embutido em equipamentos esportivos facilitando o monitoramento do atleta ou do próprio equipamento esportivo. O hardware da EESF possui um diâmetro de 63 mm, massa de 168 g, densidade de 1,1, acelerômetros triaxiais na faixa de ±200 g, comunicação sem fio no padrão ZigbeeTM, alcance de 70 m, taxa de amostragem de 438 Hz e autonomia de 45 minutos. Já o software integra duas Interfaces Gráficas de Usuário (GUI), uma para Análise em Tempo Real (RTA) e outra para Análise e Pós-Processamento (PPA), que inclui uma opção de vídeo sincronização. O segundo instrumento é uma Plataforma de Força (PF) uniaxial, de baixo custo, projetada para trabalhar tanto estática quanto dinamicamente, para uma faixa de ±2,2 kN, taxa de amostragem de até 2,4 kHz, alta Relação Sinal-ruído (SNR), alto ganho e tampo de vidro com a opção de sincronismo com vídeo por baixo da mesma. Com a EESF foram realizados testes de queda livre em laboratório, sincronizados com a PF, para comparar os valores dos impactos obtidos pelos dois instrumentos, e testes em unidades de beneficiamento de maçã e laranja para medir os impactos sofridos pelas frutas no processo de pós-colheita. A PF também foi utilizada durante os testes de repique com diferentes bolas de futebol, em sincronismo com a cinemetria, comparando os resultados obtidos com os dois sistemas e ainda caracterizando cada bola através das variáveis cinemáticas e dinâmicas. A integração de diferentes tecnologias mostrou-se uma ferramenta valiosa na análise do impacto e suas relações com o objeto em estudo. As informações colhidas de diversos instrumentos foram comparadas e cruzadas, favorecendo o entendimento da mecânica do impacto. Estes instrumentos são facilmente adaptáveis a qualquer necessidade específica dentro da análise de problemas que envolvem impacto, tendo aplicações não somente em agricultura e esporte, mas também na área médica e de materiais
Abstract: Fruits submitted to large impacts suffer irreversible damage, lose their quality and, most of the times, and can't be availed at the end of the post-harvest process. Identifying and understanding these critical events may help to reduce food losses. With reference to sports, studying the impacts related to sport equipments by taking into account their particular material characteristics, can be a valuable tool for the development and manufacture of improved sport items like soccer balls. Aiming to provide new tools to analyze and study agriculture and sports impacts, we developed two instruments including hardware and software, which interact synchronously with the kinematic method based on cameras motion analysis. The first instrument developed is a monitoring system of biomechanical variables system called Wireless Electronics Sphere (WES). In focus on agriculture, the WES electronic circuit is encapsulated inside a sphere, facilitating fruit and other perishable products is monitored through the acquisition of product quality variables. In other application focus on sport, the electronic circuit can be encapsulated, attached or embedded into sport equipment, facilitating monitoring the athlete or sports equipment. The WES hardware has a 63 mm diameter, 168 g weight, 1.1 density, triaxial accelerometers in the range of ±200 g wireless communication with ZigbeeTM standard, 70 m range, 438 Hz sampling rate and 45 minutes of battery autonomy. The software integrates two Graphical User Interfaces (GUI), one for Real-Time Analysis (RTA) and the other for Post-Processing Analysis (PPA), which includes a video synchronization option. The second instrument is a low cost uniaxial Force Platform (FP), designed to work both static and dynamically for a ±2.2 kN range, 2.4 kHz sampling rate, high Signal-to-Noise Ratio (SNR), high gain and glass top with video sync option. The WES was used in the laboratory freefall test and synchronized with the FP, to compare the impact values obtained by both instruments. Beside, the WES was tested in apple and orange packing houses to measure the impact suffered by the fruits in the post-harvest process. The FP was also used during the rebounding tests with different soccer balls, synchronized with the kinematics and the results obtained were compared with both systems and each ball was also characterized through the kinematic and dynamic variables. The integration of different technologies proved to be a valuable tool on impact analysis and its relations with the object under study. The information collected from different instruments was compared and crossed, promoting the understanding of the impact mechanic. These instruments are easily adaptable to any specific requirement in the analysis of problems involving impact, with applications not only in agriculture and sports, but also in medical and material areas
Doutorado
Eletrônica, Microeletrônica e Optoeletrônica
Doutor em Engenharia Elétrica

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Zhang, Li. "Signal processing for future MIMO-OFDM wireless communication systems." Thesis, Cardiff University, 2008. http://orca.cf.ac.uk/54757/.

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The combination of multiple-input multiple-output (MIMO) technology and orthogonal frequency division multiplexing (OFDM) is likely to provide the air-interface solution for future broadband wireless systems. A major challenge for MIMO-OFDM systems is the problem of multi-access interference (MAI) induced by the presence of multiple users transmitting over the same bandwidth. Novel signal processing techniques are therefore required to mitigate MAI and thereby increase link performance. A background review of space-time block codes (STBCs) to lever age diversity gain in MIMO systems is provided together with an introduction to OFDM. The link performance of an OFDM system is also shown to be sensitive to time-variation of the channel. Iterative minimum mean square error (MMSE) receivers are therefore proposed to overcome such time-variation. In the context of synchronous uplink transmission, a new two-step hard-decision interference cancellation receiver for STBC MIMO-OFDM is shown to have robust performance and relatively low complexity. Further improvement is obtained through employing error control coding methods and iterative algorithms. A soft output multiuser detector based on MMSE interference suppression and error correction coding at the first stage is shown by frame error rate simulations to provide significant performance improvement over the classical linear scheme. Finally, building on the "turbo principle", a low-complexity iterative interference cancellation and detection scheme is designed to provide a good compromise between the exponential computational complexity of the soft interference cancellation linear MMSE algorithm and the near-capacity performance of a scheme which uses iterative turbo processing for soft interference suppression in combination with multiuser detection.

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Lima, Ferrer de Almeida André. "Tensor modeling and signal processing for wireless communication systems." Nice, 2007. http://www.theses.fr/2007NICE4056.

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Dans plusieurs applications de traitement du signal pour les systèmes de communication sans fils, le signal reçu est de nature multidimensionnelle et possède une structure algébrique multilinéaire. Dans ce contexte, la décomposition tensorielle de type PARAFAC a fait l’objet de plusieurs travaux au cours des six dernières années. Il s’avère que des décompositions tensorielles plus générales sont nécessaires pour couvrir des classes plus larges de systèmes de communication faisant intervenir à la fois des modèles de transmission et de canal plus complexes et des méthodes de traitement plus efficaces. Cette thèse traite les problèmes de modélisation des systèmes multi-antennes, d’égalisation de canal, de séparation de signaux et d’estimation paramétrique de canal à l’aide d’approches tensorielles. Dans un premier temps, de nouvelles décompositions tensorielles (bloc-PARAFAC avec contraintes et CONFAC) ont été développées et étudiées en termes d’identifiabilité. Dans un deuxième temps, la décomposition bloc-PARAFAC avec contraintes a été appliquée tout d’abord pour mettre en évidence une modélisation tensorielle unifiée des systèmes suréchantillonnés, DS-CDMA et OFDM, avec application à l’égalisation multiutilisateur. Puis, cette décomposition a été utilisée pour modéliser des systèmes de transmission MIMO avec étalement spatio-temporel et détection aveugle. La décomposition CONFAC a ensuite été exploitée pour concevoir un nouveau schéma de transmission MIMO/CDMA combinant diversité et multiplexage spatial. Les propriétés d’unicité de cette décomposition ont permis de réaliser un traitement aveugle au niveau du récepteur pour la reconstruction du canal et des symboles transmis. Un troisième volet du travail concerne l’application de la décomposition PARAFAC pour la conception de nouveaux schémas de transmission spatio-temporel-fréquentiel pour des systèmes MIMO multiporteurs, et pour l’estimation paramétrique de canaux multitrajets
In several signal processing applications for wireless communications, the received signal is multidimensional in nature and may exhibit a multilinear algebraic structure. In this context, the PARAFAC tensor decomposition has been the subject of several works in the past six years. However, generalized tensor decompositions are necessary for covering a wider class of wireless communications systems with more complex transmission structures, more realistic channel models and more efficient receiver signal processing. This thesis investigates tensor modelling approaches for multiple-antenna systems, channel equalization, signal separation and parametric channel estimation? New tensor decompositions, namely, the block-constrained PARAFAC and CONFAC decompositions are developed and studied in terms of identifiability. Fist, the block-constrained PARAFAC decompositions applied for a unified tensor modelling of oversampled, DS-CDMA and OFDM systems applications to blind multiuser equalization. This decomposition is also used for modelling multiple-antenna (MIMO) transmission systems with block space-time spreading and blind detection, which generalizes previous tensor-based MIMO transmission models. The CONFAC decomposition is then exploited for designing new uniqueness properties of this decomposition? This thesis also studies new applications f third-order PARAFAC decomposition? A new space-time-frequency spreading system is proposed for multicarrier multiple-access systems, where this decomposition is used as a joint spreading and multiplexing tool at the transmitter using tridimensional spreading code with trilinear structure. Finally, we present a PARAC modelling approach for the parametric estimation of SIMO and MIMO multipath wireless channels with time-varying structure

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28

Moretti, Simone <1983&gt. "Data Processing and Fusion For Multi-Source Wireless Systems." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7450/.

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The constant evolution of the telecommunication technologies is one fundamental aspect that characterizes the modern era. In the context of healthcare and security, different scenarios are characterized by the presence of multiple sources of information that can support a large number of innovative services. For example, in emergency scenarios, reliable transmission of heterogeneous information (health conditions, ambient and diagnostic videos) can be a valid support for managing the first-aid operations. The presence of multiple sources of information requires a careful communication management, especially in case of limited transmission resource availability. The objective of my Ph.D. activity is to develop new optimization techniques for multimedia communications, considering emergency scenarios characterized by wireless connectivity. Different criteria are defined in order to prioritize the available heterogeneous information before transmission. The proposed solutions are based on the modern concept of content/context awareness: the transmission parameters are optimized taking into account the informative content of the data and the general context in which the information sources are located. To this purpose, novel cross-layer adaptation strategies are proposed for multiple SVC videos delivered over wireless channel. The objective is to optimize the resource allocation dynamically adjusting the overall transmitted throughput to meet the actual available bandwidth. After introducing a realistic camera network, some numerical results obtained with the proposed techniques are showed. In addition, through numerical simulations the benefits are showed, in terms of QoE, introduced by the proposed adaptive aggregation and transmission strategies applied in the context of emergency scenarios. The proposed solution is fully integrated in European research activities, including the FP7 ICT project CONCERTO. To implement, validate and demonstrate the functionalities of the proposed solutions, extensive transmission simulation campaigns are performed. Hence, the presented solutions are integrated on a common system simulator which is been developed within the CONCERTO project.

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29

Stine, John Andrew. "Energy conserving protocols for wireless data networks." Access restricted to users with UT Austin EID Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3035983.

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30

Han, Taewoo. "New signal processing in OFDM communication systems." Diss., Online access via UMI:, 2005. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3174448.

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Thesis (Ph. D.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Department of Electrical & Computer Engineering, 2005.
Includes bibliographical references.

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31

Zou, Qiyue. "Signal processing for RF distortion compensation in wireless communication systems." Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1693067881&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.

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32

Navaratnam, Srivallipuranandan. "Reliable group communication in distributed systems." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26505.

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This work describes the design and implementation details of a reliable group communication mechanism. The mechanism guarantees that messages will be received by all the operational members of the group or by none of them (atomicity). In addition, the sequence of messages will be the same at each of the recipients (order). The message ordering property can be used to simplify distributed database systems and distributed processing algorithms. The proposed mechanism continues to operate despite process, host and communication link failures (survivability). Survivability is essential in fault-tolerant applications.
Science, Faculty of
Computer Science, Department of
Graduate

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33

Huang, Wen, and 黄文. "Opportunistic scheduling in wireless data networks." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B45895235.

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34

Xu, Ji. "Data caching in wireless mobile networks /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?COMP%202004%20XU.

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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004.
Includes bibliographical references (leaves 57-60). Also available in electronic version. Access restricted to campus users.

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35

Acharya, Debopam Kumar Vijay. "Data in your space a data staging and push pull based location dependent wireless data dissemination system /." Diss., UMK access, 2006.

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Thesis (Ph. D.)--School of Computing and Engineering. University of Missouri--Kansas City, 2006.
"A dissertation in computer science and informatics and telecommunications and computer networking." Advisor: Vijay Kumar. Typescript. Vita. Title from "catalog record" of the print edition Description based on contents viewed Jan. 26, 2007. Includes bibliographical references (leaves 115-120). Online version of the print edition.

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36

Jalali, Sammuel. "Wireless Channel Equalization in Digital Communication Systems." Scholarship @ Claremont, 2012. http://scholarship.claremont.edu/cgu_etd/42.

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Our modern society has transformed to an information-demanding system, seeking voice, video, and data in quantities that could not be imagined even a decade ago. The mobility of communicators has added more challenges. One of the new challenges is to conceive highly reliable and fast communication system unaffected by the problems caused in the multipath fading wireless channels. Our quest is to remove one of the obstacles in the way of achieving ultimately fast and reliable wireless digital communication, namely Inter-Symbol Interference (ISI), the intensity of which makes the channel noise inconsequential. The theoretical background for wireless channels modeling and adaptive signal processing are covered in first two chapters of dissertation. The approach of this thesis is not based on one methodology but several algorithms and configurations that are proposed and examined to fight the ISI problem. There are two main categories of channel equalization techniques, supervised (training) and blind unsupervised (blind) modes. We have studied the application of a new and specially modified neural network requiring very short training period for the proper channel equalization in supervised mode. The promising performance in the graphs for this network is presented in chapter 4. For blind modes two distinctive methodologies are presented and studied. Chapter 3 covers the concept of multiple "cooperative" algorithms for the cases of two and three cooperative algorithms. The "select absolutely larger equalized signal" and "majority vote" methods have been used in 2-and 3-algoirithm systems respectively. Many of the demonstrated results are encouraging for further research. Chapter 5 involves the application of general concept of simulated annealing in blind mode equalization. A limited strategy of constant annealing noise is experimented for testing the simple algorithms used in multiple systems. Convergence to local stationary points of the cost function in parameter space is clearly demonstrated and that justifies the use of additional noise. The capability of the adding the random noise to release the algorithm from the local traps is established in several cases.

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37

Yatawatta, Sarod Petropulu Athina P. "Efficient signal processing techniques for future wireless communications systems /." Philadelphia, Pa. : Drexel University, 2004. http://dspace.library.drexel.edu/handle/1860/374.

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38

Liu, Jianhua. "System design and signal processing for OFDM-based wireless communication systems." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0006701.

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39

Almalki, Nazih Carleton University Dissertation Engineering Systems and Computer. "Integration of data services over wireless indoor voice communication systems." Ottawa, 1996.

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40

Wu, Xiaoting. "Array signal processing for MIMO radar /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?ECED%202009%20WU.

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41

WANG, SHU. "THE APPLICATION OF SUBSPACE TECHNOLOGIES IN WIRELESS COMMUNICATION SYSTEMS." University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1065704505.

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42

Choi, Lai U. "Multi-user MISO and MIMO transmit signal processing for wireless communication /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202003%20CHOI.

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Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003.
Includes bibliographical references (leaves 167-170). Also available in electronic version. Access restricted to campus users.

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43

Gurung, Sanjaya Acevedo Miguel Felipe. "Integrating environmental data acquisition and low cost Wi-Fi data communication." [Denton, Tex.] : University of North Texas, 2009. http://digital.library.unt.edu/ark:/67531/metadc12131.

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44

Tran, Le Chung. "Complex orthogonal space-time processing in wireless communications." Access electronically, 2006. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20060726.133841/index.html.

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45

Hsu, Wei-Tan. "Iterative post-SIC processing schemes in V-BLAST wireless MIMO communication systems." [Ames, Iowa : Iowa State University], 2007.

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46

Davies, Jessica. "Expanding the spatial data infrastructure model to support spatial wireless applications /." Connect to thesis, 2003. http://eprints.unimelb.edu.au/archive/00001044.

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47

Zhou, Yiqing, and 周一靑. "Advanced techniques for high speed wireless communications." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B29296080.

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Li, Xiao. "Channel estimation and timing synchronization in cooperative communication systems." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B42841835.

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Sandys, Sean David. "Requirement specifications for communication in distributed real-time systems /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/7002.

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50

Lillie, Andrew G. "Iterative receiver techniques for high data rate indoor wireless communication systems." Thesis, University of Bristol, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.419135.

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Dissertations / Theses on the topic 'Wireless communication systems – Data processing'

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