Rozprawy doktorskie na temat „Uplink”
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Baby, Johnson. "LTE UPLINK MODELLING AND ANALYSIS OF CARRIER FREQUENCY OFFSET ON UPLINK TRANSMISSION INTERFERENCE". Thesis, Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-24015.
Pełny tekst źródłaPrasai, Sandesh. "Access control of NUTS uplink". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for telematikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19209.
Pełny tekst źródłaMehari, Tariku Temesgen. "Frequency Hopping in LTE Uplink". Thesis, Blekinge Tekniska Högskola, Avdelningen för telekommunikationssystem, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-4232.
Pełny tekst źródłattma07@student.bth.se tariku.temesgen.mehari@ericsson.com
Ho, Kenneth T. "Uplink channel estimation in WiMAX". College Park, Md. : University of Maryland, 2008. http://hdl.handle.net/1903/8214.
Pełny tekst źródłaThesis research directed by: Dept. of Electrical and Computer Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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.
Pełny tekst źródłaThe 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.
Brännström, Nils. "Voice-over-IP over Enhanced Uplink". Thesis, Linköping University, Department of Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8479.
Pełny tekst źródłaThe traditional voice service in mobile networks is an important service that mobile users expect high quality from. With the convergence of mobile networks towards an all-IP network, an IP-based speech service becomes important which is referred to as Voice-over-IP (VoIP). The traditional voice service is highly optimized and a VoIP service must therefore fulfil strict quality requirements to provide the same speech service quality. The air interface technology, WCDMA, which is used in third generation communication systems in Europe is constantly developed. An improved concept for the mobile-to-network transmission, called the Enhanced Uplink (EUL) provides for higher uplink capacity for packet data services. It also includes features that may provide a sufficient VoIP service quality in mobile networks, when considering the uplink transmission.
The purpose of this thesis is to evaluate the VoIP capacity over EUL and identify crucial aspects of radio resource management in order to increase the capacity. This is done through dynamic system simulations, using a realistic VoIP traffic model. The VoIP capacity is also estimated by a derived theoretical framework.\newline
It is shown by simulation results and theoretical estimations, that power control is a vital mechanism in order to increase the capacity. Simulation results indicate that a VoIP over EUL capacity of 65\% of the traditional voice service capacity may be reached. The results also indicate that to improve the capacity for larger cells, the allowed VoIP packet delay must be increased.
Ahmed, Mohsin Niaz. "LTE Uplink Modeling and Channel Estimation". Thesis, Linköpings universitet, Datorteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-69571.
Pełny tekst źródłaDi, Shuang. "USB Attached Network Performance : Uplink Performance". Thesis, KTH, Kommunikationssystem, CoS, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-91529.
Pełny tekst źródłaFler och fler människor över hela världen använder ett USB-modem för att ansluta tillInternet. Detta gäller i synnerhet i Sverige, som har den största 3G-täckning i Europa.Jämförbar med fast bredband, med hjälp av ett 3G USB-modemet är en underbar upplevelseför kunden. Allt var som helst vi kan använda vår mobiltelefon är en plats som vi hartillgång till Internet, även om vi färdas i ett tåg, promenad i en park, eller sitter på stranden.Detta gör att arbeta på resande fot mycket enklare. Men kunderna inte vet om nätetgenomströmning, fördröjning, och kostnaden för anslutning passar deras behov. Dessutomfinns det också en fråga om tid att ansluta till nätverket när det inte har funnits några trafikför en tid. Men den genomströmning, fördröjning och "tid för att ansluta" när du använderett modem för att ansluta till ett trådlöst nätverk beror på flera faktorer. I denna avhandlingkommer vi att undersöka dessa faktorer. Mer specifikt avhandlingen analyserar i detaljeffekterna av att använda en USB bifogade nätverkskort, för att få större förståelse för ettsådant gränssnitt nätverk prestanda. Vi har valt att fokusera på upplänk, eftersom detförväntas ha låg kapacitet och det har inte fått lika mycket uppmärksamhet som denerlänkning prestanda.
Manssour, Jawad. "Network Coding in Uplink Cellular Systems". Thesis, KTH, Kommunikationssystem, CoS, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-48936.
Pełny tekst źródłaGoran, Alan. "Reinforcement Learning for Uplink Power Control". Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-246043.
Pełny tekst źródłaUplink effektstyrning är en funktion för resurshanteringsom styr signalens sändningseffekt från en användaranordning,det vill säga från en mobiltelefon, till ett bas-stationstorn.Det används för att maximera datahastigheterna samtidigtsom den genererade interferensen reduceras.Förstärkningsinlärning är en kraftfull inlärningsteknik.Den har förmågan att inte bara lära en artificiell agent hurman agerar utan också skapa möjligheten för agenten attlära sig själv, genom att samspela med en miljö och samlaegna erfarenheter.I detta examensarbete har vi tillämpat förstärkningsinlärningpå uplink effektstyrning, vilket möjliggör för enintelligent mjukvaruagent att dynamiskt anpassa effektenpå sändningssignalerna hos användarens enheter. Agentenlär sig att hitta lämpliga sändningseffekter för enheternagenom att välja ett värde för korrigeringssignalen med slutenslinga i uplinken. Syftet är att undersöka huruvida förstärkningsinlärningkan förbättra uplink effektstyrningen idet nya 5G-kommunikationssystemet.Problemet formulerades som en Multi-Armed banditförst och utvidgades sedan till en Contextual bandit. Viimplementerade tre olika förstärkningsinlärning algoritmerför agenten att lösa problemet. Utförandet av agenten medanvändning av var och en av de tre algoritmerna utvärderadesgenom att jämföra prestanda för uplink effektstyrningenmed och utan agenten. Med detta tillvägagångssättkunde vi upptäcka om agenten förbättrar prestanda eller inte.Från våra simuleringar upptäcktes att agenten faktisktkan hitta ett värde för korrigeringssignalen som förbättrardatahastigheten, genomflödet mätt i Mbps, av genomsnittligaanslutningar för användarenheterna. Det har däremotockså visat sig att agenten inte har ett betydande bidragavseende interferensstörningarna.
Lindén, Erik. "Iterative Channel Estimation in LTE Uplink". Thesis, KTH, Kommunikationsteori, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-147128.
Pełny tekst źródłaEn algoritm for iterativ kanalestimering i LTE-upplank foreslas. Algoritmen harlag komplexitet jamfort med MMSE-estimering. En enkel polynomiell modellanvands for att undertrycka brus over OFDM-symboler och ett DCT-baseratlter anvands for att undertrycka brus over sub-barvagor.Algoritmen har testats med era kanalmodeller och visats ge en vinst pa cirka0:5 dB med tva estimeringsitrationer, jamfort med en icke-iterativ mottagare.Algoritmen har ocksa applicerats till en MIMO-situation.En jamforelse mellan den foreslagna algoritmen och turboutjamning hargjorts.
Suárez, Real Alberto. "Resource allocation for multiuser uplink systems". Nice, 2010. http://www.theses.fr/2010NICE4077.
Pełny tekst źródłaIn this thesis we study the subject of resource allocation for uplink communication systems. When users have target rate constraints and interference cancelation is used at the base station we provide the optimal decoding order and power allocation in order to minimize the power consumption. In addition conditions are derived under which the allocation can be done in a distributed way, with only some knowledge of the statistics of the system. We then proceed to consider multiple-input multiple-output (MIMO) systems, and obtain the optimal precoding matrices such that each user maximizes its own ergodic transmission rate from the sole knowledge of the overall channel statistics. The benefits of using a coordination signal and successive decoding are analyzed. Next, a scenario in which mobile terminals can be simultaneously connected to several base stations, using non-overlapping frequency bands is considered. The optimal power allocation in terms of sum rate is derived for different receiver types and an iterative algorithm proposed to achieve the optimal allocation. Finally, we consider decentralized medium-access control in which many pairwise interactions, where users compete for a medium access opportunity, occur between randomly selected users that belong to a large population. The choice of power level is done by each user, and both team and noncooperative scenarios are analyzed
Yao, Xuefeng. "Performance analysis of massive MIMO networks". Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/18847.
Pełny tekst źródłaArkhipov, Alexander. "IFDMA for uplink mobile radio communication systems". München Utz, 2010. http://deposit.d-nb.de/cgi-bin/dokserv?id=3440635&prov=M&dokv̲ar=1&doke̲xt=htm.
Pełny tekst źródłaGeijer, Lundin Erik. "Uplink Load in CDMA Cellular Radio Systems". Doctoral thesis, Linköpings universitet, Reglerteknik, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-16299.
Pełny tekst źródłaLi, Xinyun. "LTE uplink scheduling in multi-core systems". Thesis, KTH, Kommunikationsnät, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-99190.
Pełny tekst źródłaTiwari, K. (Kushal). "PAPR aware power allocation in OFDMA uplink". Master's thesis, University of Oulu, 2015. http://urn.fi/URN:NBN:fi:oulu-201505281714.
Pełny tekst źródłaConde, Eduardo Manuel Diogo. "Detection techniques for the uplink of LTE". Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/10181.
Pełny tekst źródłaNos dias de hoje a internet móvel está em rápida expansão devido aos smart- phones e outros dispositivos móveis. Cada vez mais o acesso á Internet á feito por ligações sem fios, permitindo que os utilizadores se liguem á Internet em qualquer lugar. Devido ao aumento do número de utilizadores e de serviços e por consequente o aumento de largura de banda, é necessário implementar novas arquitecturas que consigam acomodar essas taxas de transmissão e que também sejam rentáveis para as operadoras de telecomunicações. O LTE é assim uma das tecnologias promissoras para o aumento de tráfego verificado nestes últimos anos nas redes celulares. Por detrás da tecnologia LTE estão sistemas de acesso múltiplo que usam múltiplas portadoras ortogonais baseadas no OFDM, sendo o OFDMA usado para o downlink e o SC-FDMA para o uplink. Outro conceito usado pelo LTE são os sistemas MIMO que aumentam a eficiência espectral e a taxa de transmissão de dados. Esta dissertação tem por base a camada física do LTE (camada 1 do modelo OSI), nomeadamente a comunicação de dados no sentido ascendente baseada na técnica de acesso múltiplo SC-FDMA. Foi implementada numa plataforma de simulação um receptor com um equalizador no domínio da frequência iterativo, onde foram usadas várias configurações MIMO com o meio partilhado por vários utilizadores. Os resultados obtidos permitem comparar a eficácia deste tipo de equalizadores versus os equalizadores lineares como o ZF e MMSE tanto na eliminação das interferências como na atenuação do efeito near-far. Os resultados obtidos mostraram-se bastante satisfatórios conseguindo-se remover grande parte dos efeitos da interferências entre símbolos e/ou de múltiplo acesso obtendo-se um desempenho muito próximo do obtido considerando um filtro adaptado. Para além disso a diferença de potência entre os utilizadores não afectou o desempenho do equalizador.
Nowadays, the mobile web is in an accelerated expansion brought by the introduction of smartphones and other mobile devices. Access to the Internet by wireless networks is more and more used because it allows the users to connect to the Internet anywhere. Thus, with the increase of the number of users and services whose by consequence increase the used bandwidth, there is the need to implement new architectures to cope with the demanded transmission rates while being rentable for mobile network carriers. LTE is one of the most relevant technologies to the observed increase of traffic in the last years in cellular networks. Behind this technology, multiple access systems which use multiple orthogonal subcarriers based on OFDM are used, being OFDMA used for the downlink and SC-FDMA for the uplink. Another concept used by LTE is the MIMO systems which increase the spectral efficiency and the data rate. This thesis work is based on the physical layer of LTE (layer 1 of OSI model), namely the uplink communication with its multiple access technique SC-FDMA. It was implemented in a simulation platform an iterative frequency-domain receiver where multiple MIMO configurations were used in a multiple access environment. The obtained results allows comparison of the efficacy in removing interference and also the attenuation of the nearfar effect between linear frequency domain receivers such as ZF and MMSE and iterative frequency domain receivers. The results were successful in the cancellation of inter-symbol interference and multiple access interference. The obtained performance is very close to the one obtained by the matched filter. Moreover, the difference of power between the users did not affect the performance of the equalizer.
Cunha, Rodrigo Lopes da. "Uplink video traffic determination and network optimization". Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/23487.
Pełny tekst źródłaCom o aumento do número de plataformas de transmissão de vídeo, as operadoras têm sofrido uma maior sobrecarga nas suas redes. De forma a fornecer uma melhor gestão dessas mesmas redes, garantindo qualidade de serviço a todos os clientes, torna-se necessário dar prioridade ao tráfego correspondente a vídeo aplicando novos conveitos na área das telecomunicações, como é o caso de Software-Defined Networking. Esta dissertação procura, numa primeira fase, apresentar uma revisão de vários temas relacionados com a determinação de tráfego de vídeo, Software-Defined Networking e qualidade de serviço. Posteriormente, é apresentada uma solução de uma aplicação de monitorização, que tem como objetivo, a deteção de tráfego de vídeo, de forma a ajudar na priorização de tráfego e na otimização da rede. A solução é validada através de uma implementação, baseada na performance e na baixa latência do sistema, que procura responder o mais rápido possível com informação sobre um determinado fluxo de pacotes na rede. São ainda apresentados resultados relativos a esta implementação.
With the increase of live streaming platforms, service providers have been experiencing a overhead on their networks. In order to provide a better management of these networks, ensuring quality of service to all customers, it is necessary to prioritize video traffic using new concepts being introduced into the telecommunications field, such as Software-Defined Networking. Firstly, this dissertation aims to present a review of several topics related with video traffic determination, Software-Defned Networking and quality of service. Secondly, a monitoring application solution is presented, which aims to detect video traffic in order to help the prioritization of traffic and network optimization. The solution is validated through an implementation, based on the system’s performance and low latency, which tries to reply as quickly as possible with information about a certain flow of network packets. Results related with this implementation are also presented
Jersenius, Kristina. "Uplink Channel Dependent Scheduling for Future Cellular Systems". Thesis, Linköping University, Department of Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8213.
Pełny tekst źródłaOne goal in the development of future cellular systems is to increase performance. Channel dependent scheduling can possibly contribute to a performance enhancement. It requires channel qualityinformation and uplink channel knowledge is often incomplete. This master thesis work compares channel dependent scheduling and channel independent scheduling for a Single Carrier Frequency Division Multiple Access-based uplink in time domain and time and frequencydomain assuming continuous channel quality information updates. It also evaluates different methods for providing channel quality information by investigating how the limited channel knowledge they supply affects the performance of channel dependent scheduling.
Single-cell simulations with perfect channel knowledge indicate small gains for channel dependent scheduling. Large gains are seen when performing frequency and time domain scheduling instead of only time domain scheduling. Limited channel knowledge causes performance loss for channel dependent scheduling. The performance is only slightly decreased if a method with sufficiently frequent providing of channel quality information updates is applied.
More realistic multi-cell simulations show large gains for channel dependent scheduling. It is possible that these results are influenced by link adaptation and scheduling problems due to non predictable interference when performing dynamic scheduling. In the comparison between channel dependent and channel independent scheduling the channel dependent scheduling can benefit from the fact that the selected channel dependent scheduling algorithms result in a more static scheduling than the selected channel independent scheduling algorithms do.
Shateri, Majid. "Uplink transmit beam-forming for mobile cellular networks". Thesis, University of Surrey, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538043.
Pełny tekst źródłaKarpinsky, Christopher J. (Christopher John) 1972. "Uplink multiple access techniques for satellite communication systems". Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/49644.
Pełny tekst źródłaIncludes bibliographical references (leaves 90-92).
by Christopher J. Karpinsky.
M.S.
Kedia, Namrata Rajiv. "GUCCI: Ground station Uplink Command and Control Interpreter". Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/71885.
Pełny tekst źródłaMaster of Science
TAVAKOLI, SANIJ MOHAMAD. "Uplink CoMP Capability Improvements In Heterogeneous Cellular Networks". Doctoral thesis, Politecnico di Torino, 2016. http://hdl.handle.net/11583/2644436.
Pełny tekst źródłaHearn, Christian W. "Electrical Design and Testing of an Uplink Antenna for Nanosatellite Applications". Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/35286.
Pełny tekst źródłaMaster of Science
Ha, J. Y. "WDM/SCM PON incorporating a novel CWDM uplink combiner". Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.599814.
Pełny tekst źródłaSayin, Alp. "VHF/UHF Uplink Solutions for Remote Wireless Sensor Networks". Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-123514.
Pełny tekst źródłaAziz, Babar. "Frequency synchronization for carrier allocation in uplink OFDMA systems". Phd thesis, Université de Cergy Pontoise, 2011. http://tel.archives-ouvertes.fr/tel-00767906.
Pełny tekst źródłaJiang, Ming. "Hybrid multi-user OFDM uplink systems using multiple antennas". Thesis, University of Southampton, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427404.
Pełny tekst źródłaBrandão, Maria João Pinho. "Behavioral modeling of the NB-IoT Uplink physical laye". Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/23759.
Pełny tekst źródłaA Internet das Coisas (IoT) consiste numa rede sem fios de sensores/atuadores ligados entre si e que têm a capacidade de recolher dados. Devido ao crescimento rápido do mercado IoT, as redes de longa distância e baixa potência (LPWAN) tornaram-se populares. O NarrowBand-IoT (NB-IoT), desenvolvido pela 3rd Generation Partnership Project (3GPP), é um desses protocolos. O principal objectivo desta dissertação é a implementação de uma simulação comportamental em MATLAB do NB-IoT no uplink, que será disponibilizada abertamente. Esta será focada, primariamente, na camada física e nas suas respetivas funcionalidades, nomeadamente turbo coding, modulação SC-FDMA, modelos de simulação de canal, desmodulação SC-FDMA, estimação de canal, equalizador e turbo decoding. A estimação de canal é feita usando símbolos piloto previamente conhecidos. Os modelos de canal utilizados são baseados nas especificações oficiais da 3GPP. A taxa de bits errados (BER) é calculada e usada de forma a avaliar a performance do turbo encoder e do equalizador zero forcing (ZF). Serve também como comparação quando a implementação usa esquemas de modulação diferentes (Binary Phase-Shift Keying (BPSK) e Quadrature Phase-Shift Keying (QPSK)). Além disso, os sinais gerados em MATLAB são transmitidos usando como front-end de radio-frequência (RF) uma Universal Software Radio Peripheral (USRP). Posteriormente, são recebidos, desmodulados e descodificados. Finalmente, é obtida a constelação do sinal, a BER é calculada e os resultados são analisados.
The Internet of Things (IoT) refers to a wireless network of interconnected sensors/actuators with data-collecting technologies. Low Power Wide Area Networks (LPWAN) have become popular due to the rapid growth of the IoT market. Narrowband-IoT (NB-IoT), developed by 3rd Generation Partnership Project (3GPP), is one of these protocols. The main objective of this thesis is the implementation of an open-source uplink behavioral simulator based on MATLAB. Its focus is primarily on Layer 1 (physical layer) relevant functionalities, namely turbo coding, Single-Carrier Frequency-Division Multiple Access (SC-FDMA) modulation, channel modeling, SC-FDMA demodulation, channel estimation, equalization and turbo decoding. Channel estimation is performed using known pilot symbols. The used channel models are based on the 3GPP o cial release specs. The Bit Error Rate (BER) is calculated in order to evaluate the turbo encoder and the Zero Forcing (ZF) equalizer performance, and to compare Binary Phase-Shift Keying (BPSK) and Quadrature Phase-Shift Keying (QPSK) implementations. Furthermore, the MATLAB generated signal is transmitted using a radio-frequency (RF) front-end consisting of an Universal Software Radio Peripheral (USRP). Afterwards, the signal is received, demodulated and decoded. A constellation is obtained, the BER is calculated and the results are analyzed.
chu-hen, chiou, i 邱祖恆. "A DSP-based uplink WCDMA". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/39177314510345128529.
Pełny tekst źródła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
Paramatmuni, P. K. "LTE Baseband Algorithms for Uplink". Thesis, 2013. http://raiith.iith.ac.in/721/1/EE11M1009.pdf.
Pełny tekst źródłaChang, Li-Yen, i 張立言. "Uplink-Downlink Beamforming Design for Full-duplex Cloud Radio Access Network with Wyner-Ziv uplink Compression". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/568rk9.
Pełny tekst źródła國立臺灣科技大學
電子工程系
107
In this thesis, we consider a cloud radio acess network (CRAN) with nite fronthaul capacity architecture, which includes a centralized baseband unit (BBU) pool and a set of full-duplex (FD) remote radio heads (RRHs) serving a set of half-duplex (HD) downlink and uplink mobile users. Our goal is to minimize total transmit power of RRHs and uplink mobile users under each SINR and fronthaul capacity constraints. First, we consider a per-base-station successive interference cancellation (SIC) scheme that performs Wyner-Ziv compress-and-forward at RRHs, we use half-duplex system model at RRHs and derive achievable rate for uplink users under nite fronthaul link. Further we use full-duplex system model at RRHs, compared to half-duplex model, now we have to manage the interference such as self-interference, inter- RRH interference and uplink to downlink interference. Secondorder cone program (SOCP) based algorithm is proposed to solve power minimization problem and Uplink-Downlink Duality strategies is proposed to reduce calculation complexity. Simulation results are presented to evaluate the proposed algorithms.
Huang, Yi-Shan, i 黃義珊. "Channel Estimation for Uplink WCDMA System". Thesis, 2000. http://ndltd.ncl.edu.tw/handle/41067972043122808842.
Pełny tekst źródła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.
Ho, Hsin-Che, i 何欣哲. "Pilot Design in Uplink OFDMA Systems". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/94795720010942199866.
Pełny tekst źródła國立中山大學
通訊工程研究所
96
In this thesis, One of the difficulties in the orthogonal frequency division multiple access (OFDMA) systems is the multi-user interference (MUI) induced by the carrier frequency offset (CFO). In sub-band OFDMA systems, each user occupies a consecutive and non-overlapping frequency sub-band. The pilots are usually placed at the edges of a sub-band for frequency synchronization and channel estimation. However, the both frequency synchronization and channel estimation performance are influenced seriously by the multi-user interference (MUI) induced by CFO of other users. The MUI can be reduced by inserting the guard sub-carrier between adjacent users. In this paper, a novel pilot architecture is investigated, which has the same bandwidth efficiency as the conventional guard sub-carrier insertion scheme. In addition, the proposed pilot architecture provides better carrier frequency synchronization and channel estimation performance than conventional pilot assignment. Moreover, this new pilot architecture also has MUI reduction utility.
TU, BO-HAO, i 凃柏豪. "Uplink Access Control in Narrowband IoT". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/7e7x32.
Pełny tekst źródła國立中正大學
資訊工程研究所
107
In order to provide low-power wide area network (LPWAN) services, 3GPP adopted the Narrow-Band IoT (NB-IoT) core protocol standard in June 2016, expecting NB-IoT to become the transmission communication standard used in future service networking applications, with the goal of providing a large number of IoT devices. These IoT devices will connect to NB-IoT base stations, providing a wider range of coverage with low power consumption and a better sleep mechanism to extend better battery life. In the development of the Internet of Things, the development of the NB-IoT network has encountered some challenges. First, the design of NB-IoT is used for machine type transmission. Generally, delay time is not the primary consideration for this type of transmission. However, different types of IoT devices or applications may have different tolerances for delay time. For example, for life-threatening or life-saving devices, such as emergency medical care, they would require very low latency transmission for emergency messages and thus need special treatments. Secondly, when the user equipment starts to enter the NB-IoT network, it must synchronize with the regional base station through the random access channel (RACH) procedure. The future 5G network is expected to accommodate a density of one million IoT devices per square kilometer, which will accompany with the large number of random access requirements and causes a big challenge to the random access procedure. Therefore, how to improve the random access process to handle a large number of IoT devices without affecting the transmission of emergent messages is the focus of this thesis. In this thesis, we proposed Dynamic RACH Resource Allocation (DRRA) scheme which integrates with resource allocation scheme and ACB scheme to improve the random access process. Our simulation results show that the proposed DRRA scheme is able to achieve higher access success rate and low delay of emergent message transmission type as compared to the original standard RACH procedure.
Vijayan, Divya. "Adaptive channel estimation for LTE uplink". Thesis, 2013. http://ethesis.nitrkl.ac.in/4644/1/211EC4112.pdf.
Pełny tekst źródłaWang, Xin-Jie, i 王信傑. "Differential Modulation in Uplink Massive MIMO Systems". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/89375510090922085336.
Pełny tekst źródła國立中央大學
通訊工程學系
105
Massive MIMO systems are popular studies in recent years. Differential encoding scheme is not required to transmit pilot sequence for channel estimation, so it does not cause pilot contamination. A differentially encoded QAM (quadrature amplitude modulation) scheme for uplink massive MIMO was proposed recently which outperforms conventional differential APSK (amplitude-phase shift keying) scheme for 1000 receiver antennas. In this letter, we raise and try to resolve some questions about this differential QAM scheme. We construct new tables for differentially encoded 16-QAM. We compare differential 16-QAM with differential 16-APSK for the same detector, and compare the detector with a conventional detector for the same transmitter. Simulation results show that differential 16-APSK has the best error performance for any number of receiver antennas. Besides, we propose a new scheme for uplink coherent massive MIMO. This scheme uses transmitted data signal as pilot sequences, and we also design the pilot sequences to make it orthogonal to each other, which can shorten the time of transmission of the pilot sequence.
SALAH, Mohamed. "Comparative Performance Study of LTE Uplink Schedulers". Thesis, 2011. http://hdl.handle.net/1974/6509.
Pełny tekst źródłaThesis (Master, Electrical & Computer Engineering) -- Queen's University, 2011-05-07 12:43:54.983
Peng, Chun-Chen, i 彭崇禎. "Uplink Scheduling Schemes in EPON Access Network". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/q82kx3.
Pełny tekst źródła國立交通大學
電信工程系所
92
Rapid deployment of broadband services in the residential and small business area has played an important role in the evolution of access networks. Currently, Ethernet passive optical networks (EPON) are being considered as a promising solution for the next generation access network, due to the convergence of low-cost Ethernet equipment and low-cost of fiber infrastructure. In addition, the growing demand of broadband services such as IP telephony, video on demand has urged the network operator to accelerate the deployment of full-service access networks. In this thesis, we proposed a delay-considered scheduling scheme for real-time services, i.e. voice and video service, and two fairness-considered scheduling schemes, i.e. Hybrid LQF-QLP scheme and Hybrid EQL-QLP scheme, to support non-real-time data service. The goal of the scheduling algorithm is to meet the delay bound of voice service, and to simultaneously maintain the fairness of both packet delay and packet blocking probability for non-real-time data service. Simulation results show that the proposed scheduling method can meet our goal. In addition, we proposed a prediction-based scheduling method, in which we adopt a Moving Average technique. We find that by implementing a predictor, the maximum cycle time can be extended and the system throughput can be improved. Simulation results show that the proposed scenario can improve performance well.
Chang, Shu-Hao, i 張書豪. "Physical Layer of LTE-Advanced Uplink Transmission". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/745575.
Pełny tekst źródła國立臺北科技大學
電腦與通訊研究所
102
LTE-A (Long-Term Evolution Advanced) is specified criterion for fourth generation mobile communication at present, all of fourth generation''s version are definition by Third Generation Partnership Project (3GPP). This thesis is discuss about the data bits from Transport Channels to Physical Channels for transmission process, First, Time Division Duplexing (TDD) of the LTE-A system began to introduce and explain the Frame Structure. Since the LTE-A uplink slot structure and physical resources, we introduce the uplink transmit of data bits from Transport Channels to Physical Channels for transmission process basic system architecture, and in the process of the basic architecture of each block in detail above classification. Finally, the LTE-A uplink of the Physical uplink share channel and basic system architecture is described.
Tseng, Ping-Yi, i 曾平一. "Throughput Analysis of TDD/CDMA Uplink Systems". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/96962607201581838924.
Pełny tekst źródła大葉大學
電信工程學系碩士班
94
The interference time ratio and multiple access interference from both base stations (BSs) and mobile stations (MSs) are analyzed for TDD/CDMA uplink systems, and the uplink throughput is evaluated according to a required outage probability. Only the path loss and shadowing effect in the mobile radio channel are considered in our investigating, while the effect of multi-path fading is assumed to be compensated by signal processing and channel coding. In regarding to the interference time ratio, we find that the interference time ratio increases as the cell radius increases for the interfering BSs. For the interfering MSs, the interference time ratio increases as the distance between the MS and the interfered BS decreases. In regarding to the capacity loss due to the cell size, for a 50% down-link cell coverage, when the cell radius increases from 100 m to 5,000 m and 10,000 m, the capacity loss is 45.1% and 87% respectively. For a 85% down-link cell, the loss is 37.5% and 93.7% respectively. While for a 95% down-link cell, the loss is 53.8% and 92.3% respectively. We find that the capacity loss increases as the cell radius and the cell coverage increase. Therefore it is a better choice to deploy TDD/CDMA systems in the micro-cells. Because the BSs tend to transmit more power for a higher downlink cell coverage, the associate interference also increased, and the capacity decreases accordingly. As a result, the downlink power control should be used to reduce the BSs transmitted power.
Huang, Ding-Yu, i 黃鼎御. "Hybrid Uplink Scheduling for Discontinuous Realtime Traffic". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/53495308222300323856.
Pełny tekst źródła國立暨南國際大學
電機工程學系
101
Taking the advantage of silence suppression, the communication systems need not to allocate radio resources for the users in silence state. By doing so, the system capacity can be significantly improved. The main issue for the systems with discontinuous re- altime traffic is how to immediately allocate resources, while the users reactivate and transit from the silence state to active state. Traditionally, there are two typical band- width request (BR) methods: the unicast-polling and the multicast-polling methods. The unicast-polling BR method can guarantee the bandwidth request delay, but at the cost of much more resources allocated for bandwidth requests. The multicast-polling method has lower resource overhead needed for bandwidth requests, whereas cannot ensure the bandwidth request delay because of contention collisions. In this thesis, we propose the hybrid-multicast/unicast-polling method, which combines the multicast polling and unicast polling. In the proposed hybrid BR method, we can adopt longer period for the unicast-polling to lower resource overhead used for polling, and shorter period for the multicast-polling to reduce the bandwidth request delay. To compare the hybrid-polling, unicast-polling, multicast-polling methods, we develop analytical models to evaluate bandwidth request delay, delay variance, bandwidth request failure probability, and resource overhead for BR polling. On the top of analytical mod- els, we formulate the optimization problem to determine the period of polling, and resource units in a multicast-polling contention window, aiming to minimize the re- source overhead for BR polling, under the requirements of bandwidth request delay and bandwidth request failure probability. Numerical results show that the proposed hybrid-polling method achieves comparable resource overhead for bandwidth request as the multicast-polling method, with a guaranteed bandwidth request delay. We have also performed extensive simulations to verify the analytical models. The analytical models can provide important insights for network planning to ensure the bandwidth request delay and lower resource overhead for bandwidth request.
Kuo, Sheng-Chung, i 郭勝中. "Carrier Frequency Offset Estimation for OFDMA Uplink". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/80684360018419579289.
Pełny tekst źródła國立中央大學
通訊工程研究所
98
In OFDMA uplink systems, carrier frequency offset (CFO) would cause inter carrier interference (ICI) and multiple access interference (MAI), and would degrade the system performance. Blind CFO estimation algorithms have been proposed in lot of papers, and [1] proposed the MUSIC algorithm with excellent performance, but the MUSIC algorithm includes two operation that are hard for hardware to implement, to acquire the noise subspace and grid search procedure that depends on search resolution, besides, the wireless communication system transmission unit is frame, but the channel and CFO will change along the symbols, so if we estimate the CFO per symbol isn’t efficiency, so in this paper, we applied a fast data projection method (FDPM) to get the noise subspace and proposed a iterative MUSIC scheme to estimate the CFO over frame rapidly.
Lu, Chih-Yuan, i 盧志遠. "Initial Uplink Synchronization for the IEEE 802.16e". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/24277906341120785334.
Pełny tekst źródła國立中正大學
通訊工程研究所
96
IEEE wireless MAN standard IEEE 802.16 has been considered for the next generation wireless communication system. Orthogonal frequency division multiple access (OFDMA) has recently received significant interest and has been adopted as one of the physical layer modes in the IEEE wireless MAN 802.16 standard. In the mutiuser OFDMA environment, each user is allocated with a group of subcarriers. To maintain the orthogonality among the subcarriers in the uplink of OFDMA system, the signals transmitted by all subscriber stations (SS) must arrive at the base station (BS) synchronously. This work is accomplished by an initial uplink synchronization. At the initial uplink synchronization, subscriber stations obtain the base station parameters from downlink broadcast channel. According to these parameters, each SS generates its initial ranging code and transmits two repeated initial ranging symbols to the BS. The BS then determines the ranging code under multipath fading channel for further use. In this thesis, we study the processing procedure at the BS for determining the ranging code. This procedure includes energy detection, frequency synchronization, timing synchronization, and ranging code detection.
Yin, Wei-Cheng, i 尹唯丞. "Robust Channel Estimation in LTE Uplink Transmission". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/59183133871554119116.
Pełny tekst źródła國立交通大學
電子工程學系 電子研究所
103
Wireless communication will play an important role in the evolution of communication in the future, especially basing on WiMAX (IEEE) and LTE (3GPP) to develop individually. The major difference between the two systems is that LTE using single carrier frequency division multiple access(SC-FDMA)technique in uplink transmission, while WiMAX using orthogonal frequency division multiple access(OFDMA).The advantage of using SC-FDMA is to reduce the peak-to-average power ratio (PAPR) which saves the power consumption of user equipment (UEs). This thesis will introduce the subjects of channel estimation problems, algorithms, analysis of multi-path transmission in SC-FDMA. In channel estimation, we first use the least square estimator, then use two different methods to estimate the channel frequency response. The first method is to estimate the correlation matrix of channel by the frequency response of reference signals estimated by least square estimator. Then smooth the channel response of reference signals by linear minimum-mean square error (LMMSE) matrix derived by correlation matrix. The second method is using Gaussian distribution window (GWD) to make reference signal smoother. After estimating frequency response of reference signals, we use linear interpolation to get frequency response of data subcarriers. In simulation, we test and verify the simulate model which we proposed in additive white Gaussian noise(AWGN) channel. Then we simulate in multi-path channel. We find that LMMSE has similar performance as Gaussian distribution window in low SNR, but Gaussian distribution window has lower complexity than LMMSE.
Shen, Wei-Liang, i 沈威良. "MAC Designs for Uplink Multiuser MIMO Systems". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/28868789709454722719.
Pełny tekst źródła國立臺灣大學
電機工程學研究所
103
With the popularity of mobile devices and data-intensive applications, the amount of traffic generated by existing wireless networks has been tremendously increasing. This phenomenon introduces the urgent requirement for high speed wireless transmissions. One predominate approach is Multiuser MIMO (MU-MIMO) systems, which exploit multiple antennas equipped at a phyiscal access point or a virtual access point connected by backhaul networks to enable several users to communicate simultaneously. These strategies introduce several new challenges: 1) The optimal ransmission bitrate of a user will change with the concurrent transmitters on a per packet basis.Therefore, traditional historical-based bitrate selection algorithms cannot work in MU-MIMO systems. 2) In a uplink MU-MIMO system, every single error caused by hidden terminals or collisions will corrupt the whole packets.Therefore, MU-MIMO systems are especially more vulnerable to errors than single-user networks. Simply retransmitting collided packets will take away the performance gains provided by multiple concurrent transmissions. 3) A system can further combine multiple access points as a multi-antenna virtual access point. However, in such a ``network MU-MIMO system'', arbitrarily forming several antennas as an access point could increase the probability of inter-cell interference and further decrease channel utilization. How to form practically-sized virtual access points becomes a critical problem in network MIMO systems. This dissertation tries to solve the above problems. First, this dissertation focuses on a single access point scenario, and proposes a MAC protocol for each user to properly select their bitrates based on the channels of concurrent transmitters such that the performance gain provided by MU-MIMO can be fully utilized. To address the error vulnerability problem of MU-MIMO,this dissertation proposes a packet recovery strategy for MU-MIMO systems to repair collided packets without significant overhead. Finally, this dissertation introduces a new structure for network MIMO systems, which adaptively forms practically-size virtual access points based on dynamic client distributions and traffic demands to reduce inter-cell interference and enhance antenna utilization. The above designs have been implemented on software defined radio platforms and analyzed through simulations. In both testbed experiments and simulations, the proposed systems can achieve a significant performance gain, as compared to the traditional wireless network and existing MU-MIMO systems.
Liao, Yen-Kai, i 廖彥凱. "Uplink Scheduling for LTE Video Surveillance Systems". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/20378530724742582097.
Pełny tekst źródła國立清華大學
資訊工程學系
103
Due to the proliferation of applications for the Internet of Things, an increasing number of machine to machine (M2M) devices are being deployed. In particular, one of the M2M applications, video surveillance, has been widely discussed. Long Term Evolution (LTE), which can provide a high rate of data transmission and wide range of coverage, is a promising standard to serve as an M2M video surveillance system. In this thesis, we studied a performance maximization problem in an LTE video surveillance system. Given a set of objects and a set of cameras, each camera has its own performance grade and its own coverage. The goal is to maximize the performance of the system by allocating limited resources to cameras while all objects should be monitored by the selected cameras. We propose a heuristic method to select the cameras and allocate resources to them to solve the problem. Moreover, to reduce the load of the LTE system, a dynamic adjustment method is also proposed.
Jiun-ShiangChang i 張俊翔. "The Research of WiMAX Uplink Scheduling Algorithm". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/99945582810912080184.
Pełny tekst źródła國立成功大學
電信管理研究所
98
Because of the rapid development of broadband applications in recent years, the quality of service for transmission speed and quality is increased. Hence, the QoS requirement is added in WiMAX standard. Transmission priority depends on service types that users subscribe. This priority arrangement is to ensure data transmission and to meet the application service quality. To meet the demand for QoS, IEEE 802.16e proposes five different scheduling services. When the data streams start to enter the scheduling queue, they will first be classified according to the service requirements. The purpose of classification is to provide different QoS parameters. In the Uplink scheduling algorithms, when a SS establish a connection with BS, BS will implement CAC to check whether enough bandwidth to use. Once the connection is established, BS scheduler will allocate appropriate bandwidth to users. However, the bandwidth assigned to the user may not be able to meet the scheduling service, so users need to re-allocate bandwidth to the schedule services. The goal of this study is to allocate available bandwidth to the schedule for uploading services to meet the non-real-time scheduling service. The proposed schedule method can prevent the non-real-time service from hungry and can enhance its existing bandwidth efficiency. Based on the exist schedule method, this study attempts to propose a new algorithm to improve transmission efficiency. The NS-2 simulator is employed to verify our method. A comparison of network performance between the proposed method and exist schedule method is also given in this thesis
Deng, Zhi-Hong, i 鄧治泓. "Performance analysis in uplink of 3GPP LTE". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/24578982715099904988.
Pełny tekst źródła雲林科技大學
通訊工程研究所碩士班
98
ABSTRACT The cellular technologies specified by 3GPP are the most widely deployed in the world, with more than 2.6 billion users in 2009. 3GPP LTE is the name given to a project within the 3GPP to improve the mobile phone standard to cope with future requirements. In this thesis, we investigate uplink technologies of 3GPP LTE, which is a transmission technique that utilizes single carrier modulation. Single carrier frequency division multiple access (SC-FDMA), a modified form of Orthogonal FDMA (OFDMA), is a promising technique for high data rate uplink communications in future cellular systems. SC-FDMA has similar throughput performance and essentially the same overall complexity as OFDMA. A principal advantage of SC-FDMA is the peak-to-average power ratio (PAPR), which is lower than that of OFDMA. SC-FDMA is currently a strong candidate for the uplink multiple access scheme in the Long Term Evolution of cellular systems under consideration by the Third Generation Partnership Project (3GPP). In our research, We investigate the 3GPP LTE using multiple-input multiple-output (MIMO) and single carrier frequency division multiple access (SC-FDMA) in different carrier mapping schemes to upload technology. We observe MIMO SC-FDMA uses different carrier mapping schemes have different performance. Therefore, We desired that the analysis of MIMO SC-FDMA uses a different carrier mapping schemes, which the best performance of mapping schemes.