Tesi: "WCDMA" – Grafiati

1

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.

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Multiple Access Techniques is the emerging techniques for the nextgeneration (3G) wireless communication systems. Multiple access techniques hasbeen designed to add features such as multimedia capabilities, high data rates andmulti-rate services to the existing wireless communication framework. The datarates proposed 2, 3 are 2Mbps indoor, 384 Kbps pedestrian, and 144 Kbpsvehicular. Several standards for third generation systems have been proposed anddeveloped by different industrial committees in countries such as the U.S, Europeand Japan. All the standards have accepted in one form or another as the multipleaccess method for wireless communications requirements.In this project, we study the implementation issues involved for one of theproposed multiuser channel estimation and detection algorithms for base-stations.It was found that these proposed algorithms for multiuser channel estimation anddetection have different processing and precision requirements.
Uppsatsnivå: D

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2

Hooli, K. (Kari). "Equalization in WCDMA Terminals". Doctoral thesis, University of Oulu, 2003. http://urn.fi/urn:isbn:9514271831.

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Abstract Conventional versions of linear multiuser detectors (MUD) are not feasible in the wideband code division multiple access (WCDMA) downlink due to the use of long scrambling sequences. As an alternative, linear channel equalizers restore the orthogonality of the spreading sequences lost in frequency-selective channels, thus, suppressing multiple access interference (MAI) in the WCDMA downlink. In this thesis, linear channel equalizers in WCDMA terminals are studied. The purpose of the thesis is to develop novel receivers that provide performance enhancement over conventional rake receivers with an acceptable increase in complexity, and to validate their performance under WCDMA downlink conditions. Although the WCDMA standard is emphasized as the candidate system, the receivers presented are suitable for any synchronous direct sequence code division multiple access downlink employing coherent data detection and orthogonal user or channel separation. Two adaptive channel equalizers are developed based on the constrained minimum output energy (MOE) criterion and sample matrix inversion method. An existing equalizer based on the matrix inversion lemma is also developed further to become a prefilter-rake equalizer. Performance analysis is carried out for equalizers trained using a common pilot channel and for the channel response constrained MOE (CR-MOE) and sample matrix inversion (SMI) based equalizers developed in the thesis. The linear minimum mean square error (LMMSE) channel equalizer, which assumes a random scrambling sequence, is shown to approximate the performance of the LMMSE MUD. The adaptive CR-MOE, SMI-based, and prefilter-rake equalizers are observed to attain performance close to that of an approximate LMMSE channel equalizer. The equalizers considered are also shown to be suitable for implementation with fixed-point arithmetic. The SMI-based equalizer is shown to provide good performance and to require an acceptable increase in complexity. It is also well suited for symbol rate equalization after despreading, which allows for computationally efficient receiver designs for low data rate terminals. Hence, the SMI-based equalizer is a suitable receiver candidate for both high and low data rate terminals. Adaptive equalizers are considered in conjunction with forward error correction (FEC) coding, soft handover, transmit diversity and high speed downlink packet access (HSDPA). The adaptive equalizers are shown to provide significant performance gains over the rake receiver in frequency selective channels. The performance gains provided by one antenna equalizers are noted to decrease near the edges of a cell, whereas the equalizers with two receive antennas achieve significant performance improvements also with soft handover. The performance gains of one or two antenna equalizers are shown to be marginal in conjunction with transmit antenna diversity. Otherwise the equalizers are observed to attain good signal-to-noise-plus-interference ratio performance. Therefore, they are also suitable receiver candidates for HSDPA.

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3

Peteinatos, Ilias. "WCDMA for aeronautical communications". Thesis, Brunel University, 2014. http://bura.brunel.ac.uk/handle/2438/11502.

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In this thesis, a study of the capacity of a suggested three - dimensional Air-to-Ground cellular system is being made. The Outside Cell Interference Factor (OCIF) is being calculated through simulations for reverse and forward link using seven loops, from the interfering cells around the desired cell for different values of the maximum height of the cell and its radius. Capacity per cell as well as delay and throughput for packet data transmission was calculated for the first time through closed form equations, with the use of the load factor, the activity factor and sectoring gain using the Automatic Repeat Request (ARQ) algorithm for the correction of errors. Moreover, in this thesis, the algorithm which has been created is being analyzed and used for the simulations. Moreover, for the first time, a case study has been made involving the study of capacity of the Air – to - Ground system for the airports of Greece, in three basic scenarios in which the number of the users, the delay and the throughput per cell is being calculated. In the first scenario, we are restricting to the three major airports of the country, while in the second it expands to six airports covering from the radio-coverage side almost all Greece. In the first two scenarios the same cell radius of 175 km is being used, while in the third the radius is reduced to 100 km and the airports are increased to nineteen. In all three scenarios we assume that all the users use the same service. The voice services are also studied of 12.2 kbps and data with transmission rate 64, 128 and 384 kbps. From scenarios 1 and 2 (cell radius 175 km), it was found that we can service at the same time up to 179 voice subscribers per cell at bit rate 12.2 kbps which reduces to 33 users for video call of 64 kbps and in 18 for video call of 128 kbps. In scenario 3 (cell radius 100km),it was found that we can serve at the same time until 126 voice subscribers per cell at bit rate 12.2 kbps which reduces to 23 users for video call of the 64 kbps and in 13 for video call of 128 kbps. In scenario 3 although the capacity per cell is lower than in scenarios 1 and 2, it provides greater total capacity (for all Greece) in relation to these scenarios.

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4

Törnqvist, 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.

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Power 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.

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5

Johansson, Emil, e Kim Myhrman. "GSM/WCDMA Leakage Detection System". Thesis, Linköpings universitet, Elektroniksystem, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-66963.

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Ericsson in Linkoping houses one of the largest test laboratories within thewhole Ericsson Company. Mainly, the laboratories contain equipment forGSM, WCDMA and LTE. To test these systems, a quite large number ofRadio Base Stations are needed. The RBS's are housed in a proportionatelysmall area. Instead of sending signals through the air, cables are used totransfer the RF signals. In this way the equipment communicating witheach other are well speci ed. However this may not be the case if leakageoccur.This thesis work is about developing a system for monitoring the radioenvironment and detect leakages in the test site. There is a need to de newhat a leakage really is and measurements needs to be performed in order toaccomplish this. This report describes how the work has proceeded towardsthe nal implemented solution.

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6

MOSTARDEIRO, 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.

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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Este 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.

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7

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.

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Wideband Direct-Sequence Code Division Multiple Access (W-CDMA) is the emerging protocol for the next generation (3G) wireless communication systems. W-CDMA has been designed to add features such as multimedia capabilities, high data rates and multi-rate services to the existing wireless communication framework. Several standards for third generation systems have been proposed and developed by different industrial committees in countries such as the U.S, Europe and Japan. All these standards have accepted CDMA in one form or another as the multiple access method for wireless communications requirements. In this work, we study the implementation issues involved for one of the proposed Rate Compatible Punctured Convolution Coding (RCPC) to increase information rate in WCDMA, the detection algorithms for base-stations. It was found that these proposed algorithms for detection have different processing and precision requirements. In the rate compatible punctured convolution from each coded symbol some of the bits are punctured in order to achieve the higher information rate. At the same time decoding becomes quite easy even if some of the bits from the coded symbol are not available. We have written these algorithms for a single user at ideal conditions based on theory but not practically.

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8

Persson, 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.

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The 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.

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9

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.

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To 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.

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10

Chowdhury, Moyamer, e 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.

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Wideband Code Division Multiple Access (WCDMA) is one of the main technologies for the implementation of third-generation (3G) cellular systems. It is based on radio access technique proposed by ETSI Alpha group and the specifications was finalised 1999. WCDMA is also known as UMTS and has been adopted as a standard by the ITU under the name “IMT-2000 direct spread”. The implementation of WCDMA will be a technical challenge because of its complexity and versatility. The complexity of WCDMA systems can be viewed from different angles: the complexity of each single algorithm, the complexity of the overall system and the computational complexity of a receiver. In WCDMA interface different users can simultaneously transmit at different data rates and data rates can even vary in time. WCDMA increases data transmission rates in GSM systems by using the CDMA air interface instead of TDMA. WCDMA is based on CDMA and is the technology used in UMTS. WCDMA is the dominating 3G technology, providing higher capacity for voice and data and higher data rates. The gradual evolution from today's systems is driven by demand for capacity, which is required by new and faster data based mobile services. WCDMA enables better use of available spectrum and more cost-efficient network solutions. The operator can gradually evolve from GSM to WCDMA, protecting investments by re-using the GSM core network and 2G/2.5G services. Orthogonal Frequency Division Multiplexing (OFDM) - technique for increasing the amount of information that can be carried over a wireless network uses an FDM modulation technique for transmitting large amounts of digital data over a radio wave. OFDM works by splitting the radio signal into multiple smaller sub-signals that are then transmitted simultaneously at different frequencies to the receiver. OFDM reduces the amount of crosstalk in signal transmissions. 802.11a WLAN, 802.16 and WiMAX technologies use OFDM. It's also used in the ETSI's HiperLAN/2 standard. In addition, Japan's Mobile Multimedia Access Communications (MMAC) WLAN broadband mobile technology uses OFDM. In frequency-division multiplexing, multiple signals, or carriers, are sent simultaneously over different frequencies between two points. However, FDM has an inherent problem: Wireless signals can travel multiple paths from transmitter to receiver (by bouncing off buildings, mountains and even passing airplanes); receivers can have trouble sorting all the resulting data out. Orthogonal FDM deals with this multipath problem by splitting carriers into smaller subcarriers, and then broadcasting those simultaneously. This reduces multipath distortion and reduces RF interference allowing for greater throughput. In this paper we have discussed about these two methods of third generation radio transmission system which are WCDMA and OFDM with various aspects. In between these two radio transmission technique, a better choice will be investigated.

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11

Rodriguez, Jonathan. "Adaptive rake architecture for WCDMA systems". Thesis, University of Surrey, 2004. http://epubs.surrey.ac.uk/843787/.

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WCDMA was proposed as the candidate air interface for the global 3G standard, however it will exist in three main modes of operation; the MC-CDMA to be employed in America based on the commercial IS-95 standard, with TDD, and FDD mode in Asia, and Europe. ETSI was the main European standardisation player for the evolution of the UMTS system, but activities were then passed on to the 3rd Generation Partnership Project group, which have released several versions of the standard, the latest being "Release6". Now, we are entering the early deployment phase, where recent field trials suggest that up to 384 kb/s throughput can be reasonable expected from UMTS in vehicular environments. The first round of downlink receivers will be based on the RAKE architecture, that requires advanced estimation techniques to overcome the adverse effects of the channel. In this thesis, we investigate several channel estimation techniques based on classical, and Bayesian estimation theory. We conclude that not one filter can operate satisfactorily under all channel conditions, thus providing impetus for investigating hybrid estimation schemes based on the joint application of linear interpolation with Kalman filtering. Normalised LMS algorithm, and raised cosine interpolation. In the domain of delay estimation, the MUSIC estimator performance was investigated and compared with the traditional sliding correlator filter. It was concluded that the MUSIC can provide an additional dimension in performance by overcoming the near-far effect. The main target was to address signal subspace tracking techniques to track the time-varying statistics of the channel. We concluded that the MUSIC algorithm in unison with the Minimum Description Length function, and the PASTd algorithm can provide robust performance over the required operating range. We refer to this solution as the "Adaptive MUSIC estimator". In the last chapter, we address the joint application of the raised cosine interpolation filter with the Adaptive MUSIC estimator on RAKE receiver performance. It was concluded that these two schemes could be a practical solution to the estimation problem for the first batch of UMTS receivers. In unison they provide a comprehensive solution in terms of robust estimation in low SNR environments and over the required mobile velocity range, blind detection, low complexity, and adaptivity to a time-varying channel environment.

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12

Liu, 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.

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In the modern wireless communication industry, radio communication equipment vendors not only produce communication hardware, but also produce software. In fact, software revenue is now a large part of the total revenue. As technology has developed and traffic demands increase, more and more functions required to implement the radio system are implemented via software rather than hardware. Today, many hardware functions are actually implemented with reconfigurable and programmable hardware. Therefore, it is often possible to perform an upgrade by loading new software (a software upgrade) rather than needing to change the physical hardware with every technology advance. However, introducing new elements and features in existing (often mature) software may cause unexpected problems. These problems may include new parts malfunctioning and failure or degradation of old functions. To avoid these problems, each version of software has to be thoroughly tested, not only to test the new parts, but also to verify that the old functions still work properly. Testing all the old functions is time and human resource consuming. Thus, there is an increasing demand for automated testing. This thesis will focus on why automated regression testing is necessary and how to implement automated testing in a specific environment. The thesis results show that automated testing can improve the test coverage by at least 40% for one of Ericsson’s WCDMA software releases. This coupled with a reduction in testing time enables more rapid development by significantly reducing the test time without compromising quality. All of these results lead to improved profitability and increased customer satisfaction.
I 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.

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13

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.

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It has long been recognized that in multi-cell WCDMA networks the admission of a new session into the system can have undesirable impact on the neighboring cells. Although admission control algorithms that take into account such multi-cell impact have been studied in the past, little attention has been paid to multi-cell admission and rate control algorithms when traffic is elastic. In this thesis, we propose a model for multi-cell multi-service WCDMA networks to study the impact of multi-cell admission and rate control algorithms on key performance measures such as the class-wise blocking and outage probabilities, block error rates, and the noise rise violation probabilities. By means of simulation we compare the performance of load based multi-cell algorithms with that of a single cell algorithm. We find that with multi-cell based algorithms the system capacity and performance (in terms of the above mentioned measures) are (in some cases significantly) better in homogeneous load scenarios as well as in the heterogeneous ’hotspot’ and ’hotaround’ scenarios.
Det 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’.

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14

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.

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15

Bergström, 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.

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The 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.

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16

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.

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17

Ustunel, 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.

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Thesis (M.S.)--Wichita State University, Electrical and Computer Engineering.
"May 2006." Title from PDF title page (viewed on October 19, 2006). Thesis adviser: Hyuck M. Kwon. Includes bibliographic references (leaves 40-42).

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18

Dimou, Konstantinos. "Améliorations de l'accès paquet en sens montant du WCDMA". Phd thesis, Télécom ParisTech, 2003. http://pastel.archives-ouvertes.fr/pastel-00000671.

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Les systèmes de 3G offrent de nouveaux services support (bearer services) à plus hauts débits pour les modes de transmission "paquet". Ces services vont coexister avec la voix (ou d'autres services temps réels), des scénarios de trafic mixte, voix et données, doivent être envisagés. La norme UMTS permet effectivement aux utilisateurs d'avoir plus d'un service activé simultanément. Les différentes classes de trafic augmentent la complexité de la gestion des ressources radios. Dans ce contexte, deux types de fonctions sont étudiés: l'allocation de TFCI et l'ordonnancement de paquets. Leur impact sur la qualité de service (QoS) ainsi que sur la capacité du système est évalué. On propose des améliorations de ces mécanismes dans le but d'augmenter la capacité du système et par conséquent d'améliorer la QoS des utilisateurs. Les études se restreignent au sens montant, c'est à dire aux transmissions du mobile (User Equipment ou UE) vers le réseau. Un premier mécanisme pour lequel un effort d'amélioration est fait, est l'adaptation du lien radio par variation du débit instantané transmis. On simule le cas d'une transmission multiservice (voix et données). L'UE doit partager un débit global qui lui est alloué entre les différents services activés. Ces derniers sont véhiculés dans des radio bearers (tuyaux supports). À chaque intervalle élémentaire de transmission (Transmission Time Interval, TTI), l'UE sélectionne un sous-débit pour chaque bearer; ceci se fait par la sélection d'un "format de transport" à appliquer pendant la durée TTI. Cette procédure s'effectue dans la couche MAC (Medium Access Control); le résultat de la sélection est une combinaison de formats de transport (Transport Format Combination, TFC) que la couche physique doit utiliser. La procédure, nommée sélection de TFC, permet d'adapter la transmission des différents services aux conditions variables de la propagation radio: elle détermine notablement la performance de transmission. L'algorithme de sélection de TFC est tracé dans ses grandes lignes dans la norme. Un de ses principes est de favoriser le trafic temps réel au détriment des services de données par paquet. Cependant, le trafic temps réel peut être perturbé par le trafic de données sous certaines conditions, en particulier pour les mobiles éloignés de la station de base (Node B). On propose un algorithme de sélection de TFC qui limite ces perturbations et qui offre une plus large zone de couverture aux services temps réels. En plus, il améliore la QoS du service de données et le débit effectif de l'UE sans augmenter sa puissance de transmission. Un autre type d'études concerne l'ordonnancement de paquets entre les différents utilisateurs ou UEs. C'est une procédure qui est contrôlée par la partie fixe du réseau. Nous l'étudions principalement par simulation en considérant divers mécanismes ou variations. Un premier mécanisme est nommé fast Variable Spreading Factor (fast VSF): les UEs distants changent rapidement leur facteur d'étalement (SF) afin de conserver une puissance de transmission constante, ce qui vise à stabiliser l'interférence inter-cellulaire. Un deuxième mécanisme étudié est un accès paquet décentralisé (decentralized mode) utilisant une information en retour sur le niveau global d'interférence dans la cellule. Un troisième mécanisme nommé "fast scheduling" (ordonnancement rapide) raccourcit le cycle d'ordonnancement. Les résultats ont montré que dans le cas de faible ou moyenne charge dans la cellule, le mode décentralisé réduit le délai par paquet jusqu'à 25 %. L'ordonnancement rapide augmente la capacité du système jusqu' à 10%. En plus, il améliore la QoS perçue par les utilisateurs en terme de débit par utilisateur et délai par paquet transmis.

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19

Hossain, Firoz, e 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.

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WCDMA is an interference limited multiple access technique .It is widely used in the 3rd generation mobile networks like UMTS. When a new call arrives in the system to get admission, it checks whether the call is admitted or not based on some parameters like signal to interference ratio (SIR), transmission power of the Node B and the air interface load .If the call is accepted this will increase some interference to the ongoing calls. This new interference would degrade the ongoing calls and this will also add some extra load which may also lead to the exceeding capacity. So that the system has to decide this admission policy in a systematic way that all the users should maintain their communication with guaranteed quality of service. This decision making algorithm belongs to the radio resource management functionalities of the Radio Network Controller (RNC) in a WCDMA based UMTS network. This thesis paper focuses on the mathematical representation of the call admission control in an interference based environment. There is also a comparative study with different methods.

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20

Soleimanipour, 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.

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21

De, 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.

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Unlike FDMA or TDMA systems, CDMA is interference limited and has a soft capcity that changes depending on the interference felt at the base station at a given time. Admitting a new call and user movement increases the interference level in the system. Therefore a robust Call Admission and Power Control Mechanism is needed. This thesis discusses the main approaches mentioned in the literature on Call Admission Control and Power Control and analyses two modern solutions, namely the QoS aware Power Control and Handoff Prioritization scheme introduced by [T. Rachidi, A. Y. Elbatji, M. Sebbane, and H. Bouzekri 2004] and the Received Power based simulation model discussed in [A. Capone and S. Redana 2001], in greater detail. Then we proceed to recommend improvements that are then tested in a MATLAB simulation environment. The recommended changes improve the overall dropping and handoff loss probabilities. The impact of the NRT overload mechanism discussed in [T. Rachidi, A. Y. Elbatji, M. Sebbane, and H. Bouzekri 2004] is also investigated. The investigations determined the optimum solution achievable with the NRT overload parameter settings. As the final task, a discrete time dynamic feedback control system that aims to keep the dropping and handoff loss rates for RT services below a target value regardless of the traffic dynamics or the bandwidth requirements is designed. A simple Integral Feedback controller is chosen for this task because a controller that is capable of reducing steady state error is required. The controller is used for the NRT overload mechanism while the NRT error rate is left as best effort. The controller parameters are tuned using simulations and the final result is benchmarked against two algorithms that have fixed NRT overload parameters by simulating in environments under various Poisson call arrival rates and traffic loads. The NRT overload mechanism with our controller performed best by holding the RT error rate at the required target value while producing comparatively lower NRT error rates.

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22

Khashjori, 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.

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23

Litchfield, 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.

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24

NUNES, 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.

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Abstract (sommario):

Os sistemas de comunicações móveis celulares de terceira geração trazem a promessa de oferta de serviços diversos e avançados de comunicação. Estes serviços implicam em requisitos heterogêneos de desempenho da comunicação, e na conseqüente influência de diferentes parcelas de carga sobre a infra-estrutura empregada. Este trabalho contempla a questão do planejamento, dado que pode haver cargas heterogêneas simultâneas, e avalia fatores relacionados à carga, propondo uma ferramenta para modelá-la estatisticamente, de forma que se possa escolher raios de célula apropriados como subsídio à atividade de planejamento.
Third 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.

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25

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.

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26

Türke, Ulrich. "Efficient methods for WCDMA radio network planning and optimization /". Wiesbaden : Dt. Univ.-Verl, 2007. http://www.myilibrary.com?id=134460.

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27

Dimou, 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.

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28

Wang, Ju. "Multimedia communication with cluster computing and wireless wcdma network". [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0000944.

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29

Näslund, 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.

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Abstract (sommario):

In 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.

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30

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.

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El despliegue de las redes celulares 3G/3.5G plantea un reto a las estrategias de planificación y optimización radio tradicionales. A diferencia de los sistemas 2G FDMA, cobertura y capacidad están estrechamente ligadas y deben ser tratadas conjuntamente. Además, están presentes nuevos y más sofisticados algoritmos de gestión de recursos radio (RRM) así como una concepción de red más flexible, con múltiples parámetros interdependientes con ajuste no trivial. Un nuevo paradigma de planificación radio aparece y la red se optimiza mediante complejos algoritmos ya sea estática o dinámicamente. Esta tesis doctoral supone una contribución a la optimización de las redes de acceso radio en sistemas 3G/3.5G. Varios aspectos susceptibles de mejorar la planificación han sido investigados y nuevos métodos, directrices y estrategias de análisis se proponen con el objetivo final de mejorar el rendimiento del sistema. También se han diseñado y estudiado mecanismos dinámicos que se encuentran en la frontera difusa entre la planificación y la RRM. La 1ª parte de la tesis trata la configuración de las estaciones base. El impacto de las potencias piloto, inclinación de antenas y sus interacciones con parámetros de soft handover son investigados. Se hace énfasis en los efectos más allá de los conocidos y se derivan reglas para su ajuste. A partir de los resultados, se propone una estrategia para su Planificación Automática. El objetivo final es encontrar una combinación tal que el tráfico sea ecualizado de manera efectiva entre las celdas e incrementar la capacidad del sistema. La técnica se basa en la metaheurística Simulated Annealing y es capaz de mejorar el rendimiento global de la red, representado por una función de coste con información sobre el factor de carga y sujeta a otras condiciones de calidad. La importancia de los requisitos que impone el UL, a menudo olvidados en propuestas anteriores, también se ha incluido y estudiado analíticamente. La reconfiguración de las base no es el único medio para modificar la cobertura de las celdas, en este sentido el estudio se amplía mediante la introducción de repetidores, que permiten la generación de celdas distribuidas. En este caso la planificación es más compleja debido a la aparición de nuevos efectos que no se daban en las redes clásicas 2G FDMA. La mayoría de los trabajos que tratan con repetidores tienden a ignorarlos. Por ello, la investigación se centró en el modelado y cuantificación de su impacto así como en derivar directrices de planificación. Se ha obtenido analíticamente la nueva expresión que define la región de admisión y se concluye que existe un compromiso entre capacidad y cobertura, analizado tanto teóricamente como mediante simulación. Ciertos parámetros presentan un impacto importante y se han estudiado para obtener reglas prácticas de ajuste. La variación de cobertura en la celda padre antes y después de la instalación de repetidores también ha sido modelada. Posteriormente, se propone una nueva metodología para analizar estos despliegues, teniendo en cuenta de manera realista los retardos de propagación y el comportamiento del receptor Rake. Esto permite un análisis superior con respecto a enfoques tradicionales que, en determinadas circunstancias, tienden a ofrecer cifras erróneamente optimistas. La última parte de la tesis da un paso más en la Planificación Automática y se proponen y validan 2 mecanismos dinámicos que permiten a la red reaccionar y auto-optimizarse frente a cambios en las condiciones de tráfico. El primero, basado en conclusiones anteriores, persigue detectar si uno de los enlaces presenta problemas de capacidad y, en caso afirmativo, favorecerlo para retrasar los mecanismos de control de congestión. Por último, se introduce la tecnología HSDPA y, después de analizar los recursos que deben ser compartidos con versiones previas de UMTS, se concluye que es deseable un sistema para la gestión dinámica del árbol de códigos OVSF. Se propone y valida un mecanismo que maximiza el throughput de las celdas, garantizando al mismo tiempo criterios de bloqueo y dropping.
The 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.

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31

Saur, Stephan. "Channel estimation for mobile wideband code division multiple access (WCDMA)". Aachen Shaker, 2008. http://d-nb.info/989680819/04.

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32

Yao, 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.

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33

Lee, Tung-Yi, e 李東益. "WCDMA RF design". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/59652741987741256035.

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碩士
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.

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34

Kao, Meng-Hua, e 高孟華. "Smart Antenna for WCDMA Systems". Thesis, 2001. http://ndltd.ncl.edu.tw/handle/28614832104943970371.

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碩士
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.

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35

chu-hen, chiou, e 邱祖恆. "A DSP-based uplink WCDMA". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/39177314510345128529.

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Abstract (sommario):

碩士
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

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36

Chen, Ming-Yu, e 陳明榆. "Optimization of WCDMA power amplifiers". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/59367556504237980743.

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Abstract (sommario):

碩士
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.

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37

吳怡萱. "Repeater capacity optimization in WCDMA". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/50307111784122113342.

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Abstract (sommario):

碩士
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.

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38

Chien, Po-Cheng, e 簡伯成. "WCDMA Network Design and Optimization". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/79461285123370964455.

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Abstract (sommario):

碩士
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).

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39

Huang, Chien-Jen, e 黃建人. "A WCDMA/HSDPA Baseband Transceiver". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/31212587848234169235.

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Abstract (sommario):

碩士
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.

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40

Chang, Yun-Chang, e 張允暢. "Fair packet scheduling in WCDMA". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/51838625257366696980.

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Abstract (sommario):

碩士
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.

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41

Chung, Pei-Shiun, e 鍾佩勳. "Multiuser Detection for WCDMA Systems". Thesis, 2002. http://ndltd.ncl.edu.tw/handle/38957341420912792116.

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Abstract (sommario):

碩士
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.

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42

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.

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Ο στόχος αυτής της διπλωματικής ήταν να μελετηθεί και να κατανοηθεί ο τρόπος λειτουργίας των WCDMA ασύρματων δικτύων καθώς και να υπολογιστεί η χωρητικότητα μιας κυψέλης κινητής τηλεφωνίας 3ης γενιάς. Αυτό επιτυγχάνεται μέσω του υπολογισμού των πιθανοτήτων απώλειας κλήσεων (CBP), στην κατερχόμενη ζεύξη (downlink). Δηλαδή στην περίπτωση που το σήμα αποστέλλεται από το σταθμό βάσης στον συνδρομητή. Ο υπολογισμός των πιθανοτήτων απώλειας κλήσεων είναι απαραίτητος στα WCDMA δίκτυα για τον σωστό υπολογισμό της χωρητικότητας (σε erlang) και του network dimensioning. Το αναλυτικό μοντέλο που χρησιμοποιούμαι λαμβάνει υπ’ όψιν του τα εξής: multi-service περιβάλλον, soft blocking, imperfect power control καθώς και την πολυόδευση. Τα αποτελέσματα του αναλυτικού μοντέλου συγκρίνονται μέσω προσομοίωσης και είναι αρκετά ικανοποιητικά. Τέλος εξετάζουμε και την επίδραση του orthogonality factor στην χωρητικότητα του δικτύου.
In 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.

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43

Dai, Xiaoniu. "Cell search algorithms for WCDMA systems". Thesis, 2008. http://spectrum.library.concordia.ca/976215/1/MR45457.pdf.

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Wideband Code Division Multiple Access (WCDMA) system uses orthogonal channelization codes to distinguish physical channels in a base station, while base stations are identified by different downlink scrambling codes. User equipments (UEs) must achieve synchronization to the downlink scrambling code before decoding any messages from base stations. The process of searching for a base station and synchronization to the downlink scrambling code is often referred to as cell search. The performance of cell search has a significant impact on a UE's switch-on delay, and thus it is very important to UE design. The goal of designing a cell search algorithm is to achieve a balance between speed, accuracy and complexity. A basic three-stage cell search procedure has been defined by 3GPP. It employs synchronization channels and the common pilot channel to facilitate a fast cell search. This cell search scheme only works well if there is no frequency offset between a base station's transmitter and a UE's receiver and if sampling timing is perfect on a UE. In practice, however, imperfection of oscillator in a UE may cause a big frequency error as well as clock error. It usually results in phase rotations and sampling timing drifts, which may degrade cell search performance significantly. Some advanced cell search algorithms have been proposed for mitigating impacts of frequency error or clock error. However, there is no much discussion on comprehensive solutions that can deal with the two negative impacts at the same time. In this thesis, we propose an algorithm that considers both frequency error and clock error. A fast and accurate cell search with a relatively low level of complexity is achieved. The algorithms are based on a combination of four existing enhanced cell search algorithms that are designed for a toleration of either frequency error or clock error. We first introduce the 3GPP-defined cell search algorithm as a basis. Then the four existing enhanced algorithms, PSD (partial symbol de-spreading), DDCC (differential detection with coherent combining), STS-1 (serial test in stage-1) and RSPT (random sampling per trial) are presented. Next, we propose four possible combinations of the existing algorithms: PSD+STS-1, PSD+RSPT, DDCC+STS-1 and DDCC+RSPT. Through extensive computer simulations, we find the DDCC+RSPT algorithm to be the best one. It is superior to other combinations and also outperforms any existing algorithm in terms of acquisition time, detection probability and complexity. Therefore, it is highly recommended for practical uses.

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44

Huang, Yi-Shan, e 黃義珊. "Channel Estimation for Uplink WCDMA System". Thesis, 2000. http://ndltd.ncl.edu.tw/handle/41067972043122808842.

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Abstract (sommario):

碩士
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.

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45

Hsieh, Weii, e 謝瑋一. "Adaptive LMMSE Rake Receiver in WCDMA". Thesis, 2000. http://ndltd.ncl.edu.tw/handle/90115252087328850865.

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Abstract (sommario):

碩士
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.

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46

YANG, CHUN-HUNG, e 楊俊宏. "WCDMA and DVB-T antenna design". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/67688512619272204438.

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碩士
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.

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47

Wu, Kei-Lin, e 鄔侃陵. "DOWNLINK EQUALIZER FOR 3G WCDMA SYSTEM". Thesis, 2002. http://ndltd.ncl.edu.tw/handle/98964754040189069591.

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Abstract (sommario):

碩士
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.

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48

Subramaniam, Kamala. "Radio resource management in UMTS-WCDMA systems". 2005. http://www.lib.ncsu.edu/theses/available/etd-12272005-174811/unrestricted/etd.pdf.

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49

Zhang, Hui. "Alternative code acquisition methods for WCDMA systems". Thesis, 2002. http://spectrum.library.concordia.ca/1784/1/MQ72918.pdf.

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In a CDMA cellular system, the process of the mobile station searching for a cell and achieving code and time synchronization to its downlink scrambling code is referred to as cell search. In WCDMA, the cell search is divided into five acquisition stages: slot synchronization, frame synchronization and scrambling code group identification, scrambling code identification, frequency acquisition, and cell identification. A pipelined process of the first three stages minimizes the average code and acquisition time. This report presents algorithms and results for serial search and pipeline search. The acquisition times in different cases are compared. We present six policies. A simulation testbed is used to compare the performance of the six algorithms. It is shown from the simulation results that system performance is greatly improved by using modified cell search. Our WCDMA algorithms is shown to outperform the other algorithms in all of the test situations considered (e.g., AWGN channel, four types of fading channels). In addition, our algorithm requires less time to get code acquisition than the other algorithms.

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50

Han, XiBin. "Channel estimation techniques for WCDMA communication systems". Thesis, 2004. http://spectrum.library.concordia.ca/8389/1/MR04374.pdf.

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This thesis focuses on the study of efficient channel estimation techniques for WCDMA communication systems. Some background material pertaining to wireless multipath propagation and WCDMA systems is first presented. The maximum-likelihood principle based data-aided channel estimation techniques are then investigated, resulting in two new estimation methods using pilot and information symbols. The first method combines the pilot-assisted and the decision-directed estimation schemes, yielding a much better estimation result compared to each of the two schemes alone. The second technique corresponds to an adaptive channel estimation scheme in which a new update mechanism using a variable step-size is proposed. A theoretical analysis of the mean square error of the least mean square (LMS) algorithm is conducted, showing the superiority of a variable step-size update scheme in convergence speed over the conventional constant step-size algorithm. The proposed scheme is not only able to increase the convergence speed but also can decrease the steady-state error of the adaptive estimation filter to a certain degree. The bit-error rate (BER) performance of both downlink and uplink of the WCDMA systems using the proposed channel estimation techniques is evaluated through extensive computer simulations for different mobile velocities, confirming the improved estimation accuracy of the proposed methods for both slow to fast fading channels in comparison with some of the existing techniques (Abstract shortened by UMI.)

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