Tesis sobre el tema "Time Division Multiplexing Access"
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Cen, Min. "Study on Supervision of Wavelength Division Multiplexing Passive Optical Network systems". Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-42362.
Texto completoMody, Apurva Narendra. "Signal Acquisition and Tracking for Fixed Wireless Access Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing". Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/7624.
Texto completoKong, Zhen y 孔振. "Design and analysis of cooperative and non-cooperative resource management algorithms in high performance wireless systems". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40687387.
Texto completoKong, Zhen. "Design and analysis of cooperative and non-cooperative resource management algorithms in high performance wireless systems". Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B40687387.
Texto completoQuintana, Joel. "Hybrid optical network using incoherent optical code division multiple access via optical delay lines". To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2009. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
Texto completoLowe, Darryn W. "Real-time FPGA realization of an UWB transceiver physical layer". Access electronically, 2005. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20060726.161825/index.html.
Texto completoGarro, Crevillén Eduardo. "Advanced Layered Divsion Multiplexing Technologies for Next-Gen Broadcast". Doctoral thesis, Universitat Politècnica de València, 2018. http://hdl.handle.net/10251/105559.
Texto completoSince the beginning of the 21st century, terrestrial broadcasting systems have been blamed of an inefficient use of the allocated spectrum. To increase the spectral efficiency, digital television Standards Developing Organizations settled to develop the technical evolution of the first-generation DTT systems. Among others, a primary goal of next-generation DTT systems (DVB-T2 and ATSC 3.0) is to simultaneously provide TV services to mobile and fixed devices. The major drawback of this simultaneous delivery is the different requirement of each reception condition. To address these constraints different multiplexing techniques have been considered. While DVB-T2 fulfilled the simultaneous delivery of the two services by TDM, ATSC 3.0 adopted the LDM technology. LDM can outperform TDM and FDM by taking advantage of the UEP ratio, as both services, namely layers, utilize all the frequency and time resources with different power levels. At receiver side, two implementations are distinguished, according to the intended layer. Mobile receivers are only intended to obtain the upper layer, known as CL. In order not to increase their complexity compared to single layer receivers, the lower layer, known as EL is treated as an additional noise on the CL decoding. Fixed receivers, increase their complexity, as they should performed a SIC process on the CL for getting the EL. To limit the additional complexity of fixed receivers, the LDM layers in ATSC 3.0 are configured with different error correction capabilities, but share the rest of physical layer parameters, including the TIL, the PP, the FFT size, and the GI. This dissertation investigates advanced technologies to optimize the LDM performance. A demapping optimization for the two LDM layers is first proposed. A capacity increase is achieved by the proposed algorithm, which takes into account the underlying layer shape in the demapping process. Nevertheless, the number of Euclidean distances to be computed can be significantly increased, contributing to not only more complex fixed receivers, but also more complex mobile receivers. Next, the most suitable ATSC 3.0 pilot configuration for LDM is determined. Considering the two layers share the same PP a trade-off between pilot density (CL) and data overhead (EL) arises. From the performance results, it is recommended the use of a not very dense PP, as they have been already designed to cope with long echoes and high speeds. The optimum pilot amplitude depends on the channel estimator at receivers (e.g. the minimum amplitude is recommended for a Wiener implementation, while the maximum for a FFT implementation). The potential combination of LDM with three advanced technologies that have been adopted in ATSC 3.0 is also investigated: MultiRF technologies, distributed MISO schemes, and co-located MIMO schemes. The potential use cases, the transmitter and receiver implementations, and the performance gains of the joint configurations are studied for the two LDM layers. The additional constraints of combining LDM with the advanced technologies is considered admissible, as the greatest demands (e.g. a second receiving chain) are already contemplated in ATSC 3.0. Significant gains are found for the mobile layer at pedestrian reception conditions thanks to the frequency diversity provided by MultiRF technologies. The conjunction of LDM with distributed MISO schemes provides significant performance gains on SFNs for the fixed layer with Alamouti scheme. Last, considering the complexity in the mobile receivers and the CL performance, the recommended joint configuration is MISO in the CL and MIMO in the EL.
Des de començaments del segle XXI, els sistemes de radiodifusió terrestre han sigut culpats d'un ús ineficient de l'espectre assignat. Per a augmentar l'eficiència espectral, els organismes d'estandardització de TV digital van començar a desenvolupar l'evolució tècnica dels sistemes de TDT de primera generació. Entre altres, un dels objectius principals dels sistemes de TDT de pròxima generació (DVB-T2 i el ATSC 3.0) és proporcionar simultàniament serveis de TV a dispositius mòbils i fixos. El principal inconvenient d'aquest lliurament simultani són els diferents requisits de cada condició de recepció. Per a abordar aquestes limitacions, s'han considerat diferents tècniques de multiplexació. Mentre que DVB-T2 escomet el lliurament simultani dels dos serveis mitjançant TDM, ATSC 3.0 va adoptar la Multiplexació per Divisió en Capes (LDM). LDM pot superar a TDM i a FDM en aprofitar la relació de Protecció d'Error Desigual (UEP), ja que tots dos serveis, cridats capes, utilitzen tots els recursos de freqüència i temps amb diferents nivells de potència. En el costat del receptor, es distingeixen dues implementacions, d'acord amb la capa a decodificar. Els receptors mòbils solament estan destinats a obtenir la capa superior, coneguda com Core Layer (CL). Per a no augmentar la seua complexitat en comparació amb els receptors de capa única, la capa inferior, coneguda com Enhanced Layer (EL), és tractada com un soroll addicional en la decodificació. Els receptors fixos augmenten la seua complexitat, ja que han de realitzar un procés de Cancel·lació d'Interferència (SIC) sobre la CL per a obtenir l'EL. Per a limitar la complexitat addicional dels receptors fixos, les capes de LDM en ATSC 3.0 estan configurades amb diferents capacitats de correcció, però comparteixen la resta de blocs de la capa física, inclòs el TIL, el PP, la grandària de FFT i el GI. Aquesta dissertació investiga tecnologies avançades per a optimitzar el rendiment de LDM. Primer es proposa una optimització del procés de demapeo per a les dues capes de LDM. L'algoritme proposat aconsegueix un augment de capacitat, en tenir en compte la forma de l'EL en el procés de demapeo de la CL. No obstant açò, el nombre de distàncies Euclidianes a computar pot augmentar significativament, conduint NO sols a receptors fixos més complexos, sinó també a receptors mòbils més complexos. A continuació, es determina la configuració de pilot ATSC 3.0 més adequada per a LDM. Tenint en compte que les dues capes comparteixen el mateix PP, es produeix una contrapartida entre la densitat de pilots (CL) i la redundància sobre les dades (EL). A partir dels resultats de rendiment, es recomana l'ús d'un PP no gaire dens, ja que ja han sigut dissenyats per a fer front a ecos llargs i altes velocitats. L'amplitud pilot òptima depèn de l'estimador de canal en els receptors (ex., es recomana l'amplitud mínima per a una implementació Wiener, mentre que la màxima per a una implementació FFT). També s'investiga la potencial transmissió conjunta de LDM amb tres tecnologies avançades adoptades en ATSC 3.0: les tecnologies d'agregació de MultiRF, els esquemes de MISO distribuït i els de MIMO colocalitzat. S'estudien els potencials casos d'ús, els principals aspectes d'implementació del transmissor i el receptor, i els guanys de rendiment de les configuracions conjuntes per a les dues capes de LDM. Les restriccions addicionals de combinar LDM amb les tecnologies avançades es consideren admissibles, ja que les majors demandes ja estan contemplades en ATSC 3.0 (ex., una segona cadena de recepció). S'obtenen guanys significatius per a la capa mòbil en condicions de recepció per als vianants gràcies a la diversitat en freqüència proporcionada per les tecnologies MultiRF. La conjunció de LDM amb esquemes MISO distribuïts proporciona guanys de rendiment significatius en xarxes SFN per a la capa fixa amb l'esquema d'Alamouti.
Garro Crevillén, E. (2018). Advanced Layered Divsion Multiplexing Technologies for Next-Gen Broadcast [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/105559
TESIS
Prins, Christian. "Problemes d'optimisation de ressources dans les systemes de telecommunications par satellite utilisant l'amrt (acces multiple a repartition dans le temps)". Paris 6, 1988. http://www.theses.fr/1988PA066495.
Texto completoOmomukuyo, O. O. "Orthogonal frequency division multiplexing for optical access networks". Thesis, University College London (University of London), 2013. http://discovery.ucl.ac.uk/1400463/.
Texto completoOLIVIERI, BRUNO SAPHA. "INTERROGATION SYSTEM OF FIBER BRAGG GRATING SENSORS USING TIME DIVISION MULTIPLEXING AND WAVELENGTH DIVISION MULTIPLEXING". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2004. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=5905@1.
Texto completoUm sistema de interrogação de sensores a rede de Bragg utilizando multiplexação no tempo e multiplexação no comprimento de onda é proposto e demonstrado. O sistema apresenta uma solução para a medição de grandezas associadas ao espectro de reflexão de redes de Bragg, possibilitando o aumento do número de sensores a rede de Bragg monitorados através de grandes distâncias em uma mesma fibra óptica, sem um aumento significativo dos custos. O aspecto inovador deste sistema reside na particular associação das seguintes características: o uso de fonte pulsada de banda larga, a disposição, em série, de um grande número de sensores a rede de Bragg de baixa refletividade, a técnica de reutilização dos mesmos comprimentos de onda nominais em grupos contendo vários sensores com comprimentos de onda nominais distintos e um processo de filtragem espectral e análise de sinais pulsados utilizando o filtro DWDM comercial. Aspectos teóricos e experimentais considerando os princípios de trabalho desta técnica são discutidos. Comparações entre resultados simulados e experimentais do sistema implantado mostram boa concordância. Resultados experimentais apontam uma faixa dinâmica de 1,7 nm, podendo encontrar aplicações em medição de temperatura com uma faixa de 150°C. Incertezas com valores médios abaixo de 20 picometros foram obtidas. Simulações experimentais apontam a possibilidade de utilização de um número de aproximadamente 70 sensores com 0,4% de refletividade, por comprimento de onda. Considerando a largura de banda do dispositivo DWDM (1539- 1565 nm) utilizado neste sistema, e um espaçamento de 7 nm por comprimento de onda nominal de sensor, extrapolações mostram que este número pode chegar a 210 sensores em três diferentes comprimentos de onda nominais de sensor. Considerando as bandas C e L este número pode chegar a aproximadamente 1000 sensores em 14 diferentes comprimentos de onda nominais de sensor.
An interrogation system of fiber Bragg grating sensors using time division multiplexing and wavelength division multiplexing is proposed and demonstrated. The system presents a solution to measure the magnitudes associated to the reflection spectrum of the fiber Bragg gratings, making possible to increase the number of the Bragg gratings sensors monitored through large distances at the same fiber optic, without a great increase in the costs. The innovative aspect of this system is the particular association of the following characteristics: the use of a pulsed broad band source, the disposition, in series, of a large number of low reflectivity Bragg gratings sensors, the reusing technique of the same nominal wavelengths in groups containing several numbers of sensors with distinct nominal wavelengths, and a spectral analyzing and filtering process of pulsed signals using a commercial DWDM filter. Theoretical and experimental aspects regarding the working principles of this technique are discussed. Comparisons between experimental and simulated results show a good agreement. Experimental results indicate that a dynamic range of 1,7 nm was obtained. It can be used in temperature measurement systems, with a 150°C range. Uncertainties equivalent to approximately 20 picometers was obtained. Experimental simulations indicate that it would be possible to use a number of approximately 70 sensors with 0,4% reflectivity at each nominal sensor wavelength. Considering the DWDM filter bandwidth (1539-1565 nm) used in this system, and a spectral separation of 7 nm by nominal sensor wavelength, extrapolations indicate that a number of 210 sensors can be obtained, in three different nominal sensor wavelength. Using the C-band and the L-band, a number of 1000 sensors can be obtained, in fourteen different nominal sensor wavelength.
Recio, Adolfo Leon. "Spectrum-Aware Orthogonal Frequency Division Multiplexing". Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/30193.
Texto completoPh. D.
Deckert, Thomas. "Orthogonal frequency division multiplexing based medium access under rate constraints". Dresden Vogt, 2007. http://deposit.d-nb.de/cgi-bin/dokserv?id=3002150&prov=M&dok_var=1&dok_ext=htm.
Texto completoBouziane, R. "Real-time optical orthogonal frequency division multiplexing transceivers". Thesis, University College London (University of London), 2013. http://discovery.ucl.ac.uk/1383794/.
Texto completoGao, Ruixin. "Optical packet networking using optical time division multiplexing". Thesis, Sheffield Hallam University, 2003. http://shura.shu.ac.uk/19219/.
Texto completoBrown, Trevor Junior. "Time division multiple access/code division multiple access for the optical local access network". Thesis, Manchester Metropolitan University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243716.
Texto completoLockey, R. A. "Optoelectronic time-division multiplexing for multicomponent laser doppler anemometry". Thesis, Cranfield University, 1996. http://dspace.lib.cranfield.ac.uk/handle/1826/11052.
Texto completoAkanbi, Oladeji Bamidele. "Bi-directional Dense Wavelength Division Multiplexed Systems for Broadband Access Networks". Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/13964.
Texto completoGlekas, D. "Time division multiplexing on a star coupled fibre optic network". Thesis, University of Kent, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375965.
Texto completoLu, Chun, Yihong Yan y Jian Song. "An Application of Sync Time Division Multiplexing in Telemetry System". International Foundation for Telemetering, 2013. http://hdl.handle.net/10150/579685.
Texto completoHigh speed real-time data transportation is most important for telemetry systems, especially for large-scale distributed systems. This paper introduces a STDM (Sync Time Division Multiplexing) network structure for data transportation between devices in telemetry systems. The data in these systems is transported through virtual channels between devices. In addition, a proper frame format is designed based on PCM format to meet the needs of synchronization and real-time transportation in large-scale distributed telemetry systems.
Montgomery, Michael C. "DMACS : a media access protocol for single-hop wavelength division multiplexed lightwave networks /". Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06232009-063355/.
Texto completoCheung, Chin Ying. "Noise and crosstalk analysis of all-optical time division demultiplexers". Thesis, Sheffield Hallam University, 2001. http://shura.shu.ac.uk/19455/.
Texto completoMuñiz, Rodríguez Marco Antonio [Verfasser] y Andreas [Akademischer Betreuer] Podelski. "Model checking for time division multiple access systems". Freiburg : Universität, 2015. http://d-nb.info/1119327458/34.
Texto completoCheng, Zhuo. "Hybrid Power Control in Time Division Scheduling Wideband Code Division Multiplex Access". Thesis, KTH, Kommunikationssystem, CoS, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-91097.
Texto completoMed den höga datahastighet som Enhanced Uplink (EUL) medger kan en konventionell algoritm för effektkontroll baserad på signal to interference ratio (SIR) leda till effekthöjning beroende på självinterferens eller felaktigt SIR mål. Time division (TD) schedulering vid Wideband Code Division Multiple Access (WCDMA) anses vara en nyckelfunktion för att uppnå höga datahastigheter. I övergången mellan aktiv och inaktiv transmissionstidsintervall vid time division multiplexing (TDM) har effektoscillering/effektpeak observerats. Detta gör det nödvändigt att se över algoritmerna för effektkontroll vid olika scenarion av TD schedulering. Målet med effektkontrollen i denna studie är att minimera rise over thermal noise (RoT) för en given datahastighet givet begränsningen att kvaliteten på physical layer control channel är tillräcklig (beaktande att dedicated physical control channel (DPCCH) SIR inte understiger 3dB med en sannolikhet på som mest 5%). Ett annat mål är att minimera den lokala effektoscillationen (effektpeakar) som kan inträffa till exempel vid övergång mellan aktiv och inaktiv transmissionstidsintervall. De undersökta hybrida metoderna för effektkontroll är: (1) icke-parametrisk Generalized rake receiver SIR (GSIR) Inner Loop Power Control (ILPC) vid aktiv transmissionstidsintervall + Received Signal Code Power (RSCP) ILPC vid inaktiv transmissionstidsintervall och (2) RSCP ILPC under aktiv transmissionstidsintervall + GSIR ILPC under inaktiv transmissiontidsintervall. Båda metoderna jämförs med ren GSIR och ren RSCP ILPC. Länk nivå simulering med flera användare anslutna till en enda cell visar att: Problemet med effektpeakar observeras tydligt vid GSIR + GSIR transmit power control (TPC) men generellt sett presterar den bra i alla studerade TD scenarion. GSIR presterar bättre än andra TPC metoder beträffande RoT, speciellt i TU kanal modellen. Detta beror på att metoden är bra på att motverka momentant förändrad fading och med god precision estimerar SIR. Bland alla presenterade TPC metoder är GSIR + GSIR TPC den bästa på att behålla en god kvalitet på DPCCH kanalen. Ingen effekthöjning har observerats vid GSIR + GSIR TPC. RSCP + RSCP eliminerar problemet med effektpeakar och presterar bättre än andra TPC metoder presenterade under 3GPPs Pedestrial A (pedA) 3km/h kanal beträffande RoT. Dock är metoden generellt sett sämre på att behålla kontrollkanalens kvalitet än GSIR + GSIR TPC. GSIR + GSIR ILPC eliminerar problemet med effektpeakar och presterar bättre än GSIR power control i ett scenario med 2 och 4 TDM high data rate (HDR) UE och 2 TDM HDR UE tillsammans med 4 Code Division Multiplex (CDM) LDR UE i pedA 3km/h kanalen beträffande RoT. Dock kan inte kvaliteten på kontrollkanalen behållas i detta fall heller under inaktiv transmissionstidsintervall. Det är inte rekommenderat att använda RSCP + GSIR TPC eftersom den presterar sämst av alla TPC metoder beträffande RoT i de allra flesta fall. Till dess fördel är att den är den näst bästa på att behålla kvaliteten på kontrollkanalen. Effektpeakar har observerats när RSCP + GSIR TPC använts. För att behålla kontrollkanalens kvalitet används alltid en minimum SIR nivå ovanpå alla föreslagna TPC metoder. När det finns flera anslutna TDM HDR UEs i cellen indikerar resultaten att det är en utmaning att behålla kvalitetskraven på kontrollkanalen. På grund av detta kan det bli nödvändigt att begränsa antalet anslutna terminaler i en cell i ett TD scenario.
GETANEH, WORKALEMAHU AGEREKIBRE. "Optical Time Domain Reflectometer based Wavelength Division Multiplexing Passive Optical Network Monitoring". Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-105149.
Texto completoCooper, David J. F. "Time division multiplexing of a serial fibre optic Bragg grating sensor array". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0001/MQ45424.pdf.
Texto completoPoudel, Sunil. "Study on Fault Detection andLocalization for Wave length Division Multiplexing Passive Optical Network". Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-129299.
Texto completoLam, W.-H. "Wideband time-division and spread-spectrum multiple access methods". Thesis, University of Southampton, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383353.
Texto completoUlmer, Todd G. "Resonant-cavity-enhanced surface-emitted second-harmonic generation for optical time-division demultiplexing". Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/13323.
Texto completoGross, Michael Charles. "High-rate, short-pulse sources:jitter and pedestal level in optical time-division multiplexing". Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/5405.
Texto completoLee, King F. "Space-time and space-frequency coded orthogonal frequency division multiplexing transmitter diversity techniques". Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/14981.
Texto completoWong, Kar Lun (Clarence). "Space-time-frequency channel estimation for multiple-antenna orthogonal frequency division multiplexing systems". Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100244.
Texto completoThe proposed STF channel estimator reduces to a time-frequency (TF) channel estimator when no spatial correlations exist. In another perspective, the lower-dimension TF channel estimator can be viewed as an STF channel estimator with spatial correlation mismatch for space-time-frequency selective channels.
Computer simulations were performed to study the mean-square-error (MSE) behavior with different pilot parameters. We then evaluate the suitability of our STF channel estimator on a space-frequency block coded OFDM system. Bit error rate (BER) performance degradation, with respect to perfect coherent detection, is limited to less than 2 dB at a BER of 10-5 in the modified 3GPP fast-fading suburban macro environment. Modifications to the 3GPP channel involves reducing the base station angle spread to imitate a high transmit spatial correlation scenario to emphasize the benefit of exploiting spatial correlation in our STF channel estimator.
Mody, Apurva N. "Signal acquisition and tracking for fixed wireless access multiple input multiple output othogonal frequency division multiplexing". Available online, Georgia Institute of Technology, 2004, 2004. http://etd.gatech.edu/theses/available/etd-11112004-023640/.
Texto completoDr. Alfred Andrew, Committee Member ; Dr. Ye (Geofferey) Li, Committee Member ; Dr. Nikil S. Jayant, Committee Member ; Dr. Gordon L. Stuber, Committee Chair ; Dr. Douglas B. Williams, Committee Member Vita. Includes bibliographical references.
Haumonté, Luc. "ScDMA, scattering division multiple access : a novel low-complexity reflectometry-based multiplexing system over cable networks". Nice, 2007. http://www.theses.fr/2007NICE4064.
Texto completoThe thesis proposes an extremely low-complexity multiplexing system over cable networks. The bibliographic goes through classical multiple access systems, the automotive electromagnetic environment, and the propagation into cable networks. A noise model is proposed to model electromagnetic interferences. The multi-path propagation model is validated with measurements. The multiple reflections are therefore perfectly deterministic and controllable. The latter conclusion leads us to the idea of exploiting them in order to achieve multiplexing. The innovative solution baptized ScDMA is based on reflectometry measurements: the transmitters encode data information by simply varying their termination impedances (for instance binary information 0/1 might be encoded with a switch between matched impedance and open circuit). The receiver sends some signals carefully selected, measure the reflected signals and decode the information by using classification algorithms. The performance of this new communication method is investigated: theoretical capacity from the information theory perspective, data rate physical limitations, error rate theoretical limits, and maximum number of transmitters. System-level trade-off when desiging the whole system are presented. The last chapter describes the prototype realized as a proof of concept. The novel multiple access system (ScDMA) and its features are innovative. Numerous perspectives still remain
Chheda, Shital Ratilal. "A Comparison Between Synchronous CDMA and Orthogonal Frequency Division Multiplexing (OFDM) for Fixed Broadband Wireless Access". Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/31896.
Texto completo
This thesis aims to provide a preliminary study on using TD-SCDMA and OFDM for broadband wireless systems. Currently, there is not enough theory and information to establish the feasibility of using either of these technologies for broadband wireless access. First, the basic features and background on synchronous CDMA and OFDM are presented for the reader to better understand these technologies. Then, an example TD-SCDMA system is described, and some analytical and experimental results are presented. Finally, TD-SCDMAâ s technologies, along with this systemâ s attributes, are compared analytically to that of Vector OFDM (VOFDM).
Master of Science
Cheung, Joseph Chung Shing. "Adaptive equalisers for wideband time division multiple access mobile radio". Thesis, University of Southampton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315319.
Texto completoBuot, Theodore V. "Reservation-time division multiple access protocols for wireless personal communications /". Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phb944.pdf.
Texto completoGross, Michael Charles. "High-rate, short-pulse sources jitter and pedestal level in optical time-division multiplexing /". Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04082004-180157/unrestricted/gross%5Fmichael%5Fc%5F200312%5Fphd.pdf.
Texto completoUmrani, Fahim Aziz. "Applications of perfect difference codes in fiber-optics and wireless optical code-division multiplexing/multiple-access systems". Thesis, University of South Wales, 2009. https://pure.southwales.ac.uk/en/studentthesis/applications-of-perfect-difference-codes-in-fiberoptics-and-wireless-optical-codedivision-multiplexingmultipleaccess-systems(4025609f-d2a6-4c46-9578-784403202887).html.
Texto completoTan, Kim Leong. "Dynamic holography using ferroelectric liquid crystal on silicon spatial light modulators". Thesis, University of Cambridge, 1999. https://www.repository.cam.ac.uk/handle/1810/251678.
Texto completoAndersson, Edvin. "Dataöverföring av skilda datatyper på gemensam länk via multiplexing". Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-35616.
Texto completoWhen transferring different data types between two sites, they have historically been transferred on separate infrastructures; analog signals separately, and digital data separately. Within the aviation industry, both these data types are still handled today, as transition from analog voice data to digital voice data takes time. To simplify the infrastructure, it is desirable to send all data on the same medium. Time Division Multiplexing (TDM) makes this possible and has been studied with focus on robustness and performance. The study has focused on how TDM devices should be configured with respect to Ethernet frame size to fully utilize link capacity. Theoretical reasoning has been validated by experimental data performed on TDM devices coupled with a fiber link. The number of lost frames for the system has been measured while varying data rates. This was repeated for several Ethernet frame sizes. Smaller frame sizes showed a higher possible transfer rate before data loss was recorded. This shows coherence between theory and experiments. Larger frame sizes were less good at filling the TDM time slots, causing data buffer on the device to overflow faster than for smaller frame sizes. This created data loss in the system. Other factors, such as overhead and payload, implies that the frame size should be chosen by application. Smaller data volumes that are sent frequently have an advantage when using smaller frame sizes, while when handling largeramounts of data that need to be transmitted quickly, it is more efficient to use larger frame sizes
Tureli, Didem Kivanc. "Resource allocation for multicarrier communications /". Thesis, Connect to this title online; UW restricted, 2005. http://hdl.handle.net/1773/6068.
Texto completoMacedo, Aleandro Soares. "Antenna sector-time division multiple access system for indoor wireless communications". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0014/NQ35234.pdf.
Texto completoMacfarlane, Justin Ray. "Wavelength and time division multiplexing with lightpath trespassing for all-optical star local area networks". Thesis, University of Canterbury. Computer Science, 1998. http://hdl.handle.net/10092/9380.
Texto completoAlluri, Veerendra Bhargav. "MULTIPLE CHANNEL COHERENT AMPLITUDE MODULATED (AM) TIME DIVISION MULTIPLEXING (TDM) SOFTWARE DEFINED RADIO (SDR) RECEIVER". UKnowledge, 2008. http://uknowledge.uky.edu/gradschool_theses/499.
Texto completoParent, Marc-Antoine. "Third generation mobile communications : capacity of a time-division duplex code-division multiple access cellular system". Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=29543.
Texto completoThe goal is to establish the probability that a new connection attempt be successful as a function of the instantaneous load on the network. The sought capacity is evaluated with the help of an analytical model and a simulation tool. Both tools used a so-called system-level approach. The model and the simulator were developed based on 3GPP's standard and available data from link-level simulations.
Some of the significant results presented are: (1) A maximum of around 7 to 9 orthogonal codes can be used per timeslot. (2) A UMTS TDD CDMA system should be used in pico- and micro-cellular environments in order to support efficient data transmissions. (3) The multicode interference is often wrongfully neglected in capacity studies. (4) Capacity is downlink interference-limited, even with a modest MUD efficiency.
Chen, Wei Zhang Ruifeng. "Time- frequency- selective channel estimation of ofdm systems /". Philadelphia, Pa. : Drexel University, 2005. http://dspace.library.drexel.edu/handle/1860/616.
Texto completoEdalat, Farinaz 1979. "Real-time sub-carrier Adaptive Modulation and Coding in wideband Orthogonal Frequency Division Multiplexing wireless systems". Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/43031.
Texto completoIncludes bibliographical references (p. 153-159).
The increasing demand for high speed wireless connectivity at low cost proposes new challenges for communication systems designers to implement solutions that increase the data rate by utilizing the limited radio resources more efficiently at a low additional complexity. Sub-carrier Adaptive Modulation and Coding (AMC) exploits the high frequency diversity in wideband Orthogonal Frequency Division Multiplexing (OFDM) channels to obtain higher data rates. While prior work has discussed the value of sub-carrier AMC from a theoretical perspective, this work presents the design and performance of a real-time sub-carrier AMC system. We describe our OFDM transceiver prototype, which implements real-time subcarrier AMC for a wideband wireless channel. We discuss how our design achieves accurate and consistent Signal-to-Noise Ratio (SNR) estimates, which are critical for the success of AMC. We compare the performance of sub-carrier AMC with a non-adaptive scheme that assigns the same modulation and channel coding to all sub-carriers that can support that modulation and coding for the target Bit Error Rate (BER). For a conservative comparison, we compare against the uniform modulation/coding assignment that achieves the highest data rate. Our experiments over the wireless channel show that for a target coded BER of 10-5, our system achieves average data rates of 308.3 and 237.1 Mbps across a variety of Line-of-Sight (LOS) and Non Line-of-Sight (NLOS) locations respectively, which result in 34% and 40% gain over the best non-adaptive scheme. Equivalently, such data rate gain from AMC translates to an SNR improvement of 3 dB. Finally, our implementation of AMC incurs a low overhead of 1.1% of the data rate, and a reasonable complexity, occupying 9.95% of the total transceiver gates on the Field Programmable Gate Array (FPGA).
by Farinaz Edalat.
Ph.D.
Baker, Dirk A. "Space-time block coding with imperfect channel estimates". Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=1843.
Texto completoTitle from document title page. Document formatted into pages; contains iv, 74 p. : ill. Includes abstract. Includes bibliographical references (p. 73-74).
Xu, Guoda, John Bartha, Sean Zhang, Wei Qiu, Freddie Lin, Stuart McNamee y Larry Rheaume. "Electro-Optic Hybrid Rotary Joint (EOHRJ)". International Foundation for Telemetering, 2000. http://hdl.handle.net/10150/606501.
Texto completoAn advanced electro-optic hybrid rotary joint (EOHRJ) has been developed in Phase II of an AF SBIR effort with Physical Optics Corporation (POC) to replace cable wrap structure for multi-channel rotation-to-fixed (RTF) signal transmission. The EOHRJ meets AFFTC and other range special needs with a generic, high performance, rotary joint solution. At the moment, we have successfully installed and tested the EOHRJ on our KTM tracker system with the following capabilities: 1) able to accommodate hundreds of transmission channels, including electrical power, control, feedback, and low-speed signals; 2) able to accommodate multiple channel, high data rate (over gigabits per second), and bi-directional signal transmission; 3) able to be reliable for harsh environmental operation, adaptive to stringent sized requirement, and accommodating existing electrical and mechanical interfaces. The completed EOHRJ contains three uniquely integrated functional rings. The first and the outmost one is power ring, which provides RTF transmission channels for over 50 high voltage and high current channels. The second and the middle one is low speed electrical signal ring, which provides RTF transmission for over hundred control, feedback, and low speed data signals. The third and the inmost one is optical fiber slip ring, which, incorporating with current advanced signal multiplexing technologies (either time division or wavelength division multiplexing ) is able to provide multiple channel, high data rate, and bi-directional signal transmission. At the moment, the prototype module of the tree-layer EOHRJ has been successfully assembled in Air Force’s tracker system, and is providing a satisfactory performance. This paper presents our joint work on this project.
Karaoglu, Bulent. "A comparison of frequency offset estimation methods in Orthogonal Frequency Division Multiplexing (OFDM) systems". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Dec%5FKaraoglu.pdf.
Texto completoThesis Advisor(s): Roberto Cristi, Murali Tummala. Includes bibliographical references (p. 45-46). Also available online.