Tesis sobre el tema "WCDMA"
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Suresh, Babu Kongaleti. "WCDMA in GSM". Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-18838.
Texto completoUppsatsnivå: D
Hooli, K. (Kari). "Equalization in WCDMA Terminals". Doctoral thesis, University of Oulu, 2003. http://urn.fi/urn:isbn:9514271831.
Texto completoPeteinatos, Ilias. "WCDMA for aeronautical communications". Thesis, Brunel University, 2014. http://bura.brunel.ac.uk/handle/2438/11502.
Texto completoTörnqvist, David. "Transmission Timing in WCDMA terminals". Thesis, Linköping University, Department of Electrical Engineering, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1592.
Texto completoPower control is one of the technologies used to utilize the radio resources as efficient as possible in WCDMA. The transmission power is adjusted to transmit with the lowest power level possible while the required received signal quality is maintained. Since there are large variation in channel quality over time, the power has to be adjusted to compensate for these variations. During moments of bad channel conditions a high transmission power has to be used which will to a greater extent interfere with other users in the system.
To solve this problem a concept called transmission timing was proposed. The basic idea is that the transmitter avoids data transmission during the short periods of bad channel conditions caused by fast fading. Higher bit rates can be used to compensate for this when the channel conditions are good.
In this thesis the performance of transmission timing applied to uplink data transmissions is evaluated. This is accomplished through a theoretical analysis as well as simulations of a cellular system using transmission timing. Lowered transmission power is achieved and thus lowered interference is induced. Simulations showed that the transmission power can be lowered by up to 1.6 dB compared to ordinary continuous transmission with equal average data rate. These results are however strongly dependent on the used radio environment. It is also showed that transmission timing provides increased system stability in case of rapid changes in the load situation.
Johansson, Emil y Kim Myhrman. "GSM/WCDMA Leakage Detection System". Thesis, Linköpings universitet, Elektroniksystem, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-66963.
Texto completoMOSTARDEIRO, MARIANA. "METHODS FOR WCDMA SYSTEMS PLANNING". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2003. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=5095@1.
Texto completoEste trabalho apresenta um estudo detalhado de técnicas de planejamento de sistemas celulares de terceira geração WCDMA. Primeiramente é realizado um estudo teórico do sistema WCDMA, da estrutura da interface aérea, dos diversos tipos de canais presentes no downlink e no uplink. A seguir são aprentadas técnicas de planejamento de rede, com uma análise detalhada do cálculo de enlace e do planejamento de cobertura do sistema celular. Com base neste estudo foram realizadas diversas simulações com o software aberto NPSW para diferentes situações em relação a tipos de serviço, condições de uso e carga no sistema. Estas simulações permitiram caracterizar os efeitos dos diversos parâmetros de entrada no desempenho do sistema. Finalmente, é apresentado um estudo de caso de planejamento para a região do centro do Rio de Janeiro.
This work presents a detailed study of planning tecniques for third generation WCDMA cellular systems. At first a theoretical study of the WCDMA system is presented, including the structure of the air interface and the various channel types in the downlink and uplink. Following, network planning techniques are presented, with a detailed analysis of the link budget calculations and the system coverage planning issues. Based on this study, the system behaviour was simulated using the open software NPSW for different configurations of service, operation condition and system load. The simulations allowed the characterization of the effect of several parameters on the system performance. Finally, a case study of coverage planning for downtown Rio de Janeiro is presented.
RAO, THUMATI VENKATA. "DATA PROCESSING DESIGN OF WIDEBAND CODE DIVISION MULTIPLE ACCESS (WCDMA)". Thesis, Blekinge Tekniska Högskola, Avdelningen för signalbehandling, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-1318.
Texto completoPersson, Markus. "Uplink TDMA Potential in WCDMA Systems". Thesis, Linköping University, Department of Electrical Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-11399.
Texto completoThe evolvement of the uplink in the third generation mobile telecommunication system is an ongoing process. The Enhanced Uplink (EUL) concept is being developed to meet the expected need from more advanced services, like video streaming and mobile broadband. One idea for further improvement in the EUL concept is to introduce Time Division Multiple Access (TDMA), which is studied in this master thesis.
The master thesis assignment is to study the consequences of introducing TDMA in EUL. The goal has been to identify the gains and problems, and how they can be handled. A derived theoretical framework and system simulations, using a radio network simulator, are used.
The overall conclusion is that there is a potentially large gain with an introduction of TDMA in EUL. Simulations in favorable conditions have shown that the system throughput can increase by 100% when there are only User Equipment (UE) that are using EUL in the system and by 50% when there is a mix of speech and EUL UE’s. When using TDMA the uplink load also shows improvements, the mean is generally higher but the variance is generally smaller.
Due to major differences in experienced interference between passive and active UE’s, the signal quality will vary a lot. The big variation in signal quality is identified as the main problem with introducing TDMA in EUL. It is shown that this problem can generate extreme high uplink load, which have a negative impact both on the resource efficiency and the coverage.
Folkeson, Tea. "WCDMA User Equipment Output Power Calibration". Thesis, Linköping University, Department of Electrical Engineering, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1691.
Texto completoTo save time in Flextronics high volume production, the time for test and calibration of mobile telephones need to be as short and accurate as possible. In the wideband code division multiple access (WCDMA) case, the output power calibration is the most critical calibration concerning accuracy. The aim with this thesis was to find a faster calibration method than the one that exists today and still retain accuracy.
The Third Generation Partnership Project (3GPP) outlines the requirements of the output power and they must be thoroughly considered when choosing calibration method. Measurement accuracy and the behavior of the transmitter chain parameters also must be considered.
The output power in the WCDMA phone studied is controlled by seven parameters. The parameters are characterized in this thesis, and are found to be too hardware dependent to be predicted or to be seen as predictions from each other.
Since no parameter predictions are possible it was stated that all parameters have to be measured, and a new way of measuring them in a faster way is proposed. The principle of the new measurement method is presented, and the implemented software is tested and evaluated. The new method mainly makes use of the spectrum analyzer zero span function.
The evaluation shows that the new method is faster than the original and retains accuracy. The measurement uncertainties even seem to diminish, which implicates decreased temperature dependence due to faster measurement time.
Chowdhury, Moyamer y Aminul Alam. "Study Comparison of WCDMA and OFDM". Thesis, Blekinge Tekniska Högskola, Avdelningen för telekommunikationssystem, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-1363.
Texto completoRodriguez, Jonathan. "Adaptive rake architecture for WCDMA systems". Thesis, University of Surrey, 2004. http://epubs.surrey.ac.uk/843787/.
Texto completoLiu, Yike. "WCDMA Test Automation Workflow Analysis and Implementation". Thesis, KTH, Kommunikationssystem, CoS, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-91528.
Texto completoI den moderna trådlösa kommunikationen industrin, radioutrustning leverantörerna inte bara producera kommunikation hårdvara, utan också producera mjukvara. Faktum är programvara inkomster är nu en stor del av de totala inkomsterna. Eftersom tekniken har utvecklat och trafik krav ökar, fler och fler funktioner som krävs att genomföra radiosystem genomförs via mjukvara istället för maskinvara. Många hårdvara fungerar faktiskt genomförs med omkonfigurerbara och programmerbar hårdvara. Därför är det ofta möjligt att utföra en uppgradering av lastning ny programvara (en mjukvaruversionen) snarare än behöver för att ändra den fysiska hårdvaran med varje teknik förväg. Men att införa nya element och funktioner i befintliga (ofta äldre) programvara kan orsaka oväntade problem. Dessa problem kan innehålla nya delar brister och fel eller försämring av gamla funktioner. För att undvika dessa problem, varje version av programvaran måste testas, inte bara att testa de nya delarna, men även för att kontrollera att de gamla funktionerna fortfarande arbete ordentligt. Testa alla gamla funktioner konsumera tid och personal. Således finns det en ökad efterfrågan på automatiserade tester. Den här avhandlingen kommer att fokusera på varför automatiserad regression testning krävs och hur man genomföra automatiserade tester i en viss miljö. Avhandlingen visar att automatiserade tester kan förbättra testbunt täckning med minst 40% för ett av Ericssons WCDMA programversionerna. Detta i kombination med en minskning av provning tid möjliggör en snabbare utveckling av avsevärt minska test tid utan att kompromissa med kvaliteten. Alla dessa resultat leda till bättre lönsamhet och ökat kundvärde belåtenhet.
Azzolin, de Carvalho Pires Gustavo. "Multi-Cell Admission Control for WCDMA Networks". Thesis, KTH, Kommunikationssystem, CoS, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-92203.
Texto completoDet har länge varit känt att i multi-cellulära WCDMA nät så kan insläppandet av en ny användarei systemet ha en icke önskvärd effekt på intilliggande celler. Fastän insläppskontrollalgoritmer (AC)som tar hänsyn till sådana multi-cellulära effekter har studerats tidigare, så har endast begränsaduppmärksamhet ägnatsåt multi-cellulär insläpps- och bittaktskontrollalgoritmer när trafiken är elastisk.I detta arbete föreslår vi en modell för WCDMA-nät med multipla celler och multipla tjänster ochsom är applicerbar för studier av av hur multi-cellulär insläpps- och bittaktskontroll inverkar påviktiga prestandamått som klassvisa spärr- och utslagningssannolikheter, blockfelssannolikheter, ochsannolikheten för överträdande av tillåten interferensnivå. Med simuleringar jämför vi prestanda förlastbaserade multi-cellalgoritmer med prestanda för singel-cellalgoritmer. Vi har funnit att med multicellalgoritmerså är systemskapacitetet och prestanda (i termer av tidigare nämnda mått) i några fallbetydligt bättre i homogena lastscenarier, samt i heterogena lastscenarier av typerna ’hotspot’ och’hotround’.
Rice, Garrey William. "On delay tracking strategies for WCDMA receivers". Thesis, University of Strathclyde, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401436.
Texto completoBergström, Andreas. "Packet Data Flow Control in Evolved WCDMA Networks". Thesis, Linköping University, Department of Electrical Engineering, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-4881.
Texto completoThe key idea of the new, shared high-capacity channel HSDPA, is to adapt the transmission rate to fast variations in the current radio conditions, thus enabling download peak data rates much higher than what WCDMA can offer today. This has induced a need for data that traverses the mobile network to be intermediately buffered in the Radio Base Station, RBS. A scheduling algorithm then basically selects the user with the most beneficial instantaneous radio conditions for access to the high-speed channel and transmission of its data over the air interface.
The purpose of this thesis is to design a flow control algorithm for the transmission of data packets between the network node directly above the RBS, the RNC, and the RBS. This flow control algorithm should keep the level of the buffers in the RBS on such a level that the air interface may be fully utilized. Yet it is not desirable with large buffers since e.g., this induces longer round-trip times as well as loss of all data in the buffers whenever the user moves to another cell and a handover is performed. Theoretical argumentations and simulations show that both of these requirements may be met, even though it is a balancing act.
Suggested is a control-theoretic framework in which the level in the RBS buffers are kept sufficiently large by taking into account predictions of future outflow over air and by using methods to compensate for outstanding data on the transport network. This makes it possible to keep the buffer levels stable and high enough to fully utilize the air interface. By using a more flexible adaptive control algorithm, it is shown possible to reach an even higher utilization of the air interface with the same or even lower buffering, which reduces the amount of data lost upon handovers. This loss is shown to be even more reduced by actively taking system messages about upcoming handover events into account as well.
Ahn, Dae-Young. "Interference management and code planning in WCDMA UMTS". Thesis, University of Surrey, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252354.
Texto completoUstunel, Eser Kwon Hyuck M. "Time division duplex-wideband code division multiplex (TDD-WCDMA)". Diss., Click here for available full-text of this thesis, 2006. http://library.wichita.edu/digitallibrary/etd/2006/t029.pdf.
Texto completo"May 2006." Title from PDF title page (viewed on October 19, 2006). Thesis adviser: Hyuck M. Kwon. Includes bibliographic references (leaves 40-42).
Dimou, Konstantinos. "Améliorations de l'accès paquet en sens montant du WCDMA". Phd thesis, Télécom ParisTech, 2003. http://pastel.archives-ouvertes.fr/pastel-00000671.
Texto completoHossain, Firoz y Abu-Shadat-Mohammad Sohab. "Mathematical Modelling of Call Admission Control in WCDMA Network". Thesis, Blekinge Tekniska Högskola, Avdelningen för signalbehandling, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-2933.
Texto completoSoleimanipour, Majid. "Modeling and resource management in wireless multimedia WCDMA systems". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0020/NQ38272.pdf.
Texto completoDe, Alwis Priyan Mihira. "Call admission control and resource utilization in WCDMA networks". Thesis, University of Canterbury. Electrical Engineering, 2005. http://hdl.handle.net/10092/9608.
Texto completoKhashjori, Nazem Lefteh. "Macrodiversity architecture of WCDMA with radio over fibre networks". Thesis, University of Kent, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399596.
Texto completoLitchfield, Charan. "Single user diversity receivers for frequency selective WCDMA channels". Thesis, University of Kent, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.443772.
Texto completoNUNES, WALDIR GALLUZZI. "PLANNING OF THIRD GENERATION MOBILE COMMUNICATION SYSTEMS (WCDMA-FDD)". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2002. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=2764@1.
Texto completoThird generation mobile communication systems bring the promise of several and advanced communication services, which implies in heterogeneous performance requirements and consequent influence of diferent weighted loads over the communication infra-structure aplyed. This work treats the planning issue, given that there can be heterogeneous simultaneous loads, evaluating factors relateds to this loads and proposing a tool for its tatistical modeling, which allows to choose apropriated cell rays in aid of planning procedures.
Turke, Ulrich. "Efficient methods for WCDMA radio network planning and optimization". Wiesbaden : Dt. Univ.-Verl, 2007. https://www.lib.umn.edu/slog.phtml?url=http://www.myilibrary.com?id=134460.
Texto completoTürke, Ulrich. "Efficient methods for WCDMA radio network planning and optimization /". Wiesbaden : Dt. Univ.-Verl, 2007. http://www.myilibrary.com?id=134460.
Texto completoDimou, Konstantinos. "Améliorations de l'accès paquet en sens montant du WCDMA /". Paris : École nationale supérieure des télécommunications, 2004. http://catalogue.bnf.fr/ark:/12148/cb39239459h.
Texto completoWang, Ju. "Multimedia communication with cluster computing and wireless wcdma network". [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0000944.
Texto completoNäslund, Lars. "Benchmarking of mobile network simulator, with real network data". Thesis, Linköping University, Department of Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-9185.
Texto completoIn the radio network simulator used in this thesis the radio network from a specific operator is modeled. The real network model in the simulator uses, a 3-D building database, realistic site data (antenna types, feederloss, ...) and parameter setting from field. In addition traffic statistics are collected from the customer’s network for the modeled area. The traffic payload is used as input to the simulator and creates an inhomogeneous traffic distribution over the area. One of the outputs from the simulator is power per cell.
The purposes of this thesis are to identify simulation accuracy compared to reality and to evaluate and improve the simulation models and the methods used when making a simulation of a real WCDMA network with the Astrid simulator.
In cellular systems the transmitted power influences the interference in the network and the interference is in turn affecting the performance. As the transmitted RBS power influences the downlink interference, it is important that the RBS power level is accurate in the simulator. Therefore the simulated RBS power is benchmarked with the real RBS power. The traffic payload from the real network is used as input into the simulator. Based on the traffic payload the simulator generates RBS power as output. The simulated RBS power is then compared with the measured RBS power.
It has been found that the standard parameter setting in the simulator gives in average about 1 W too much RBS power used in the simulations compared to reality. After investigation it was detected that two reasons for the overestimated power are that the common control channels (CCCH) power setting and the feederloss is not set to the same values as in field. With the new CCCH settings and feederloss the simulator overestimates the RBS power with 0.5 W in average. As the traffic today is relatively low the parameters that only affect the dedicated channels can only be used to make small adjustments of the simulated RBS power.
García, Lozano Mario. "Contribution to wireless access optimization and dynamic enhancement of WCDMA networks". Doctoral thesis, Universitat Politècnica de Catalunya, 2009. http://hdl.handle.net/10803/22707.
Texto completoThe deployment of 3G/3.5G cellular networks challenges traditional radio planning and optimization strategies. Unlike FDMA based 2G systems, coverage and capacity are tightly coupled and must be treated as a whole. Besides new and more sophisticated Radio Resource Management (RRM) algorithms are present along with a more flexible network with many interdependent parameters, whose joint adjustment is not trivial. A new radio planning paradigm appears in which the radio network is optimized by means of complex algorithms both in a static and a dynamic way. This Ph.D. thesis provides a contribution to the radio network optimization of 3G/3.5G networks. Several issues to improve radio network planning have been investigated and new methods, guidelines and strategies of analysis have been proposed with the final objective of enhancing the wireless access network performance. Dynamic mechanisms being in the blurred line between radio planning and RRM are also devised and studied. The first part of this dissertation deals with the configuration of Base Stations (BSs) the impact of pilot powers, downtilt of antennas and interactions thereof with Soft Handover parameters are investigated. Effects beyond well-known facts are outlined and new planning guidelines are derived. Given the results, an Automatic Planning strategy is devised to automate the configuration of these parameters and to find a combination such as traffic is effectively equalized among cells and a higher capacity is achieved. The technique is based on the Simulated Annealing metaheuristic and is able to improve the global performance of the network, represented by a cost function containing information on the load factor and subject to other quality constraints. The importance of uplink (UL) requirements, usually missed by existent proposals, has been also included and analytically addressed. Reconfiguring BSs is not the only means to modify cell shapes, in this sense the study is extended by introducing repeaters, which allow generating distributed coverage areas. This is the context of the second part of the thesis. New effects not present in FDMA based 2G systems imply that the radio planning process becomes more complex. Most existent papers dealing with repeaters in WCDMA networks, ignore these effects or claim their irrelevance. That is why the research work was focused in modeling them, quantifying their impact and deriving radio planning guidelines to enhance the final performance of the radio access network. The new expression for the feasibility condition has been analytically obtained showing a tradeoff between capacity and coverage. This has been analyzed both theoretically and by means of simulations and the adjustment of several parameters which have a significant impact is discussed to derive practical rules of thumb. Variation on the coverage of the donor cell before and after installing repeaters is also modeled. Subsequently, it is proposed a new methodology to analyze WCDMA networks with repeaters deployment, considering realistically path delays and the behavior of Rake receivers. This allows an enhanced analysis with respect to traditional approaches which, under certain circumstances, tend to provide erroneously optimistic metrics. The final part of the dissertation goes one step further in Automatic Planning and two dynamic mechanisms are proposed and validated so that the network can react and self tune in front of changes in traffic conditions. The first one follows some previous conclusions and aims at detecting if one of the links has capacity problems and if so, favors it to delay congestion control actions. Finally, HSDPA technology is introduced and, after analyzing the resources to be shared with a previous release of UMTS, it is concluded that a system that dynamically manages the OVSF code tree is desired. A mechanism aiming at maximizing cell throughput while guaranteeing blocking and dropping criteria is proposed and validated.
Saur, Stephan. "Channel estimation for mobile wideband code division multiple access (WCDMA)". Aachen Shaker, 2008. http://d-nb.info/989680819/04.
Texto completoYao, Na. "A CBR approach for radiation pattern control in WCDMA networks". Thesis, Queen Mary, University of London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442062.
Texto completoLee, Tung-Yi y 李東益. "WCDMA RF design". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/59652741987741256035.
Texto completo國立中央大學
通訊工程研究所碩士在職專班
96
Along with the fast development of electronics science and technology, electronics science and technology also follows to change with each passing day, Bell invent the wired communication phone (1876) to shorten the person and others'' distance up to now, and in recent years of the microchip slice high technology develop quickly and make wireless communication more universal. The the convenience of the wireless communication are used to gradually replace a wired telephone. Thesis proposes to invest and research the WCDMA cellular phone receiver to increase it’s sensitivity, and signal to noise ratio, shorten development schedule by the proprietor, increase a competition ability in the third generation mobile communication the service of the industry, and going deep in to probe into its WCDMA the radio frequency front end the analysis of design.
Kao, Meng-Hua y 高孟華. "Smart Antenna for WCDMA Systems". Thesis, 2001. http://ndltd.ncl.edu.tw/handle/28614832104943970371.
Texto completo國立臺灣大學
電信工程學研究所
89
For the 3rd Generation Partnership Project (3GPP)’s WCDMA uplink communications, scrambling is introduced in the dedicated physical channels (DCH). A specially designed matched filter, whose coefficients are a combination of the Orthogonal Variable Spreading Factor (OVSF) code and the scrambling code for the desired user, is employed to carry out the despreading and unscrambling simultaneously. Channel estimation taking advantages of the coherent integration and incoherent integration operations to enhance signal power and suppress interference at the same time, therefore improves the estimates. Besides, smart antennas hold great promise for increasing the capacity depending on radiating and receiving energy only in the intended directions. The spatial diversity is well taken by smart antennas with Digital BeamForming (DBF). The Fast Fourier Transform (FFT)-based beam-space beamforming gets the Direction-Of-Arrival (DOA) by collecting signals in a time slice; otherwise, the Minimum-Mean-Square- Error (MMSE)-based adaptive beamforming decides the weights by minimizing the mean square errors between the signals and the scrambling code. Compare these two approaches of beamforming in Signal-to-Interference and Noise Ratio (SINR) analysis to evaluate the system performance, as smart antenna is employed on WCDMA. Simulation results show that adaptive antenna provides feasible implementation.
chu-hen, chiou y 邱祖恆. "A DSP-based uplink WCDMA". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/39177314510345128529.
Texto completo國立臺灣大學
電信工程學研究所
92
With the advance of integrated circuits and communication technology, mobile communication has been widely used in daily life. The service and contents also become more and more diversified. Therefore, third generation mobile communication service has emerged to become the future of telecommunication. To meet the massive requirements of bandwidth and avoid signal interference and noise, researchers around the world work hard with the focus on channeling characteristics. The purpose of using equalizer, rake receiver, and smart antenna technology is to reduce the influence of channeling effect and hence maintain certain quality of service. However, such technologies necessitate complex circuits. It is a mammoth challenge to design with new signal processing technology without increasing volume and power consumption of circuits at the same time. In this research, the transceiver of a third generation mobile communication system is analyzed and studied. Several concerns are brought up in the fabrication process of wideband code division multiple access transceiver. Programmable logic array chipsets are also used to test and verify signal transmission in the real world. Through extensive experiments it is expected to understand the function of whole system and the application model of channel measurement data
Chen, Ming-Yu y 陳明榆. "Optimization of WCDMA power amplifiers". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/59367556504237980743.
Texto completo元智大學
通訊工程學系
99
The optimization studies of RF power amplifier (PA) in AWU-6601 MMIC by ANADIGICS Inc. for WCDMA system are presented, by using some peripheral circuitries including DC-DC converter TPS-62040 from TI Inc. and low pass filter at the power supply. The DC-DC converter improves the PA efficiency by adjusting the handset battery to the optimum voltage; and the associated low pass filter reduces the inter-modulation distortion caused by the low frequency interference from power supply circuit to improve ACLR asymmetry. Finally, the X-parameter measurements are performed for the PA to demonstrate the various nonlinear parameters acquired by the X-parameter computation to accelerate the RD cycle accurately and efficiently. The thesis also addresses the future directions for PA designs and measurements.
吳怡萱. "Repeater capacity optimization in WCDMA". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/50307111784122113342.
Texto completo國立交通大學
電子研究所
99
Repeaters have been employed on analogue and 2G generation mobile networks, which are designed to support voice, low data rates and short messages. The 3G mobile systems are designed to support high speed internet access with high transmission quality. The use of repeaters, to enhance the weak RF signals, taking the quality of service and costs into consideration is important. However repeater can enlarge interference and we must manage the deployment and the gain of repeater under tight control. In the thesis the main target is to optimize the system performance by appropriately adjusting repeater parameters. We first investigate the influence of repeater at three different kinds of scenarios to find a case in which optimization can be applied. Later the optimization formula is proposed and turned into a linear problem. We then do optimization on multi-cell system by adjusting parameters, i.e. repeater gain, SINR threshold etc, to suppress severe interference and improve system performance. An algorithm is proposed to give a more specifically criterion to adjust the parameters. The simulation results show repeater can effectively enhance user SINR and spectrum efficiency at no other-cell-variation interference circumstance and balance the tradeoff between system capacity and user SINR.
Chien, Po-Cheng y 簡伯成. "WCDMA Network Design and Optimization". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/79461285123370964455.
Texto completo國立中央大學
通訊工程研究所碩士在職專班
96
In radio network, besides build new sites to improve cell coverage to offer more service, the site design and pre-tuning of Radio Base Station (RBS) will effected network’s performance deeply. In this book, we focus on Wideband Code Division Multiple Access (WCDMA) network’s optimization, and research better solution to decrease drop call rate on high speed objects to keep stable signal level and quality. There are 5 chapters in this book. The chapter 1 is introduction research objective. The chapter 2 described the network structure of WCDMA, and mention about radio resource control. The chapter 3 introduced WCDMA network’s hardware, channel mapping, cell selection and reselection. The chapter 4 is focus on radio access network (RAN) tuning. And mention about in high speed object how we adjusted site’s hardware and parameter to avoid frequency shift (Doppler Effect).
Huang, Chien-Jen y 黃建人. "A WCDMA/HSDPA Baseband Transceiver". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/31212587848234169235.
Texto completo國立清華大學
電機工程學系
93
In this thesis, WCDMA communication systems and HSDPA systems are presented. Then, we propose a baseband transceiver architecture for HSDPA communication systems and its circuit design. In order to improve the transmission data rate in downlink WCDMA communication systems, 3GPP has proposed HSDPA communication systems in Release 4 and Release 5 documents. After system specification description, a baseband transceiver for HSDPA communication systems is proposed. In this proposed transceiver, we focus on receiver design. We use Common Pilot Channel (CPICH) to achieve channel estimation and restore High-Speed Share Control Channel (HS-SCCH) and High-Speed Physical Downlink Share Channel (HS-PDSCH) data. Receiver can mainly be divided into four parts: synchronization, equalization, de-spreading and symbol recovery. The synchronization part includes a channel estimator, a carrier frequency synchronization, and a timing synchronization. In channel estimator, the multiple-dwell detection is introduced to minimize the size and power consumption of matched filter. Besides, applicable algorithms is adopted to design the frequency synchronization loop, timing synchronization loop, and adaptive equalizer base on low cost and practical criterion but without losing performance even better. The detail architecture and algorithm of each reception technique in receiver will be presented in the thesis. After system functional simulation based on propagation conditions of multi-path Doppler fading environment in 3GPP for HSDPA with carrier frequency and timing offset inserted, the circuit design of the proposed HSDPA transceiver will be mentioned. Matched filter and time domain LMS equalizer are the dominant components in receiver. Via coarse comparison and evaluation of the hardware cost and computation complexity, hardware reduction from modified detection algorithm and the emphasis of hardware implementation of whole receiver can be addressed clearly. Finally, some future works and the conclusions of this thesis will be given.
Chang, Yun-Chang y 張允暢. "Fair packet scheduling in WCDMA". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/51838625257366696980.
Texto completo國立交通大學
資訊工程系
91
Abstract There is a lot of research on fair scheduling of delay and rate-sensitive packet flows over time division multiple access (TDMA) wireless cellular networks. But none of them can be applied directly to wideband code division multiple access (WCDMA), which is the major trend in 3G telecommunication, without loss of channel utilization because of the code rate constraints and channel error behavior in WCDMA. In this paper, we first apply idealized wireless fair scheduling (IWFQ) directly to WCDMA system. We derive the worst case delay and throughput bounds for this algorithm. Then we modify IWFQ to achieve higher channel utilization to approximate the ideal fairness of IWFQ. Finally, we describe a scheduling algorithm based on a credit/debit scheme in comparison with virtual time-based algorithm. Through simulations, we show that the lack of efficiency of IWFQ and the advantages of the proposed algorithms.
Chung, Pei-Shiun y 鍾佩勳. "Multiuser Detection for WCDMA Systems". Thesis, 2002. http://ndltd.ncl.edu.tw/handle/38957341420912792116.
Texto completo國立臺灣大學
電信工程學研究所
90
The structure of the multiuser decorrelating detection is considered for the uplink asynchronous transmission based on the technique of the code-division multiple-access over the time-varying frequency selective fading channel. The aim of the thesis is to validate and evaluate the feasibility and the performance under the third generation mobile communication for this advanced receiver structure. Based on the general system model of the asynchronous transmission, we find that the processing window can be set as two symbol intervals without loss of performance. Some problems may arise for the asynchronous system model when some equivalent spreading codes contain all zeros. We address the problem and prevent the singularity of the direct matrix inversion. By adopting the conjugate gradient algorithm, a kind of iterative algorithm, the singularity problem can be excluded by a unified treatment. This iterative algorithm converges with a small number of iterations and needn’t compute the matrix inversion of high complexity. For the multipath fading environment, it can be combined with the concept of maximum ratio combining straightforwardly. Under the practical system, we need to estimate the propagation delay and received amplitude. We combine the inaccuracy of channel estimation and the advantage of the decorrelating detector to evaluate the bit error rate in the third generation system with perfect power control over a frequency selective fading channel. Based on the simulation results, it can be shown that the decorrelating detector can be degraded by the erroneous estimation of the delay and amplitude. Moreover, the decorrelating receiver is suitable for the high data rate transmission but in the low rate the performance of the decorrelating detector is inferior to that of the conventional matched filter although using additional computations.
Δασκαλόπουλος, Ιωάννης. "Μελέτη των δικτύων WCDMA 3ης γενιάς και υπολογισμός της χωρητικότητας μιας WCDMA κυψέλης στην κάτω ζεύξη". Thesis, 2009. http://nemertes.lis.upatras.gr/jspui/handle/10889/1620.
Texto completoIn WCDMA networks, the Call Blocking Probability (CBP) assessment is necessary for proper cell capacity determination, in respect of traffic load in erlangs, and network dimensioning. This paper focuses on the downlink capacity estimation, through CBP calculation in a WCDMA cell. To this end, we construct an analytical model for the WCDMA cell by taking into consideration the effects of the following: the multi-service environment, soft blocking, imperfect power control and multipath propagation. To analyze the system, we describe the WCDMA cell by a Markov chain, where each system state represents a certain number of resources occupied by the mobile users. We solve the Markov state and provide an efficient recurrent formula for the system occupancy distribution, as well as the so-called local blocking probabilities. Based on them, we calculate the CBP of different service-classes accommodated in the cell versus the total offered traffic load. The WCDMA cell capacity in erlangs is determined by the maximum traffic load which satisfies certain CBP (CBP boundary) per service-class. We evaluate the analytical model through simulation. The results show that the accuracy of the model is very satisfactory. In addition, we show the effect of the intra-cell interference (due to orthogonality factor) on the erlang capacity of the cell.
Dai, Xiaoniu. "Cell search algorithms for WCDMA systems". Thesis, 2008. http://spectrum.library.concordia.ca/976215/1/MR45457.pdf.
Texto completoHuang, Yi-Shan y 黃義珊. "Channel Estimation for Uplink WCDMA System". Thesis, 2000. http://ndltd.ncl.edu.tw/handle/41067972043122808842.
Texto completo國立交通大學
電子工程系
88
In this thesis, the channel estimation methods for next generation wideband code-division multiple-access (WCDMA) system were studied. Coherent WCDMA reverse link periodically transmitting pilot symbols in front of every control channel slot to estimate the fading channel is considered. For the WCDMA reverse link, fast transmit power control (TPC) and power saving of mobile station are the important issues. We proposed moving average method and sliding window methods to overcome the decision delay of the control symbols. We also proposed a low-complexity channel estimation method based on both control and data channels to reduce the required power of a control channel. After investigation and simulation in this thesis, we conclude that the sliding window type-VI channel estimation based on both control and data channels is better than other methods in the overall performance of BER, delay time and power reduction.
Hsieh, Weii y 謝瑋一. "Adaptive LMMSE Rake Receiver in WCDMA". Thesis, 2000. http://ndltd.ncl.edu.tw/handle/90115252087328850865.
Texto completo國立交通大學
電子工程系
88
This thesis proposes a modified adaptive LMMSE algorithm to significantly improve the performance of the rake receiver in the case of high data rate situation, while reducing computational complexity, compared with conventional approach. The modified LMMSE algorithms also lead to a more stable convergence performance. The thesis also extensively studies the rake receiver, which is an important component in the third Generation Mobile Communication (Wideband Code Division Multiple Access) systems.
YANG, CHUN-HUNG y 楊俊宏. "WCDMA and DVB-T antenna design". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/67688512619272204438.
Texto completo國立中央大學
通訊工程研究所碩士在職專班
96
The major topic of the thesis is advancing a novel method to combine the DVB-T and W-CDMA antennas system for reducing the space in UMPC (ultra mobile personal computer). Using a high frequency diplexer and a muti-band resonance antenna, it can integrate the DVB-T and W-CDMA system antennas into one antenna with little extra components. That is, the method save one of the DVB-T and W-CDMA system antenna and gain the benefit to drop the cost and the space in UMPC. For example, a W-CDMA antenna space is65x6.5x4mm and place on the top of the monitor of the UMPC. It is a half of the volume which uses two antennas system. Therefore, the goodness of the method provided by the thesis can increase the spaces utility rate of the space and down its cost.
Wu, Kei-Lin y 鄔侃陵. "DOWNLINK EQUALIZER FOR 3G WCDMA SYSTEM". Thesis, 2002. http://ndltd.ncl.edu.tw/handle/98964754040189069591.
Texto completo國立臺灣大學
電信工程學研究所
90
In 3G WCDMA downlink, the effect of the wireless communication multi-path channel will destroy the orthogonality of different user’s spreading code, thus the multiple-access interference (MAI) arises and degrades the system performance. In demand of high data rates in 3G cellular system, how to efficiently reduce the MAI to improve the system performance is the most important thing. In this thesis, we propose using a chip-level equalizer to oppose the multi-path channel and thus the orthogonality of different user can be recovered. Furthermore, we suggest using the diversity technique to help the equalizer perform much better. The most important factor which will affect an equalizer’s performance is how to adjust the equalizer’s coefficients according to various communication channel. In this part, we first derive a matrix solution of equalizer’s coefficients. This matrix solution needs to know the information of communication channel. Thus, we introduce a least-square channel estimator to estimate the communication channel. Although the chip-level equalizer with the matrix solution to calculate the equalizer’s coefficients can efficiently reduce the MAI, it will need to calculate the inversion of a large rank matrix. This is a big problem in implementing this chip-level equalizer on hardware. Thus, we establish two adaptive algorithms to calculate the equalizer’s coefficients based on the structure of rank-reduced multi-stage Wiener filter. From the implement of these adaptive algorithms, we can obtain the balance between the system performance and computational complexity.
Subramaniam, Kamala. "Radio resource management in UMTS-WCDMA systems". 2005. http://www.lib.ncsu.edu/theses/available/etd-12272005-174811/unrestricted/etd.pdf.
Texto completoZhang, Hui. "Alternative code acquisition methods for WCDMA systems". Thesis, 2002. http://spectrum.library.concordia.ca/1784/1/MQ72918.pdf.
Texto completoHan, XiBin. "Channel estimation techniques for WCDMA communication systems". Thesis, 2004. http://spectrum.library.concordia.ca/8389/1/MR04374.pdf.
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