Dissertations / Theses: 'Wireless communication systems Relay control systems'

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Wu, Victor Kai Yuen. "OFDM-based cooperative communications in a single path relay network and a multiple path relay network." Thesis, Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-11092006-152421/.

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Garcia, Gilbert O. Joseforsky David C. "Transformational communications architecture for the Unit Operations Center (UOC) ; Common Aviation Command and Control System (CAC2S) ; and Command and Control on-the-move Network, Digital over-the-horizon Relay (CoNDOR) /." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Jun%5FGarcia%5FJoseforsky.pdf.

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Xing, Chengwen, and 邢成文. "Linear minimum mean-square-error transceiver design for amplify-and-forward multiple antenna relaying systems." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44769738.

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Joseforsky, David C., and Gilbert O. Garcia. "Transformational communications architecture for the Unit Operations Center (UOC), Common Aviation Command and Control System (CAC2S), and Command and Control On-the-Move Network, Digital Over-the-Horizon Relay (CoNDOR)." Thesis, Monterey California. Naval Postgraduate School, 2004. http://hdl.handle.net/10945/1586.

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Approved for public release, distribution is unlimited
The purpose of this research was to introduce a Transformational Communications Architecture for the Unit Operations Center (UOC); Common Aviation Command and Control System (CAC2S); and Command and Control On-the- Move Network, Digital Over-the-Horizon Relay (CoNDOR). The methodology used was to conduct Field Tests with government contractors and private vendors in order to demonstrate the capabilities of each wireless technology researched. These wireless technologies, Free Space Optics (FSO), Microwave, 802.16, 802.11b over SecNet-11, Orthogonal Frequency Division Multiplexing (OFDM), Broadband Satellite, INMARSAT, and Iridium, all have the potential of being implemented in the transformational communications architecture for intra-nodal and inter-nodal links for UOC and CAC2S, as well as the CoNDOR communications architecture. The ultimate goal of this research was to introduce different technologies that offer more flexibility, mobility, and capability at the tactical level giving the Marine Corps the tactical wireless edge. Throughout this research, the focus revolved around testing equipment and network configurations in an IP network. Special consideration was given to wireless issues for the UOC, CAC2S, and CoNDOR, which could improve line-of-sight, beyond line-of-sight, and over-the-horizon communications for each program. These new technologies will transform communications in the United States Marine Corps for the 21st century.
Captain, United States Marine Corps

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Bui, Tuyen Thi Bich Electrical Engineering &amp Telecommunications Faculty of Engineering UNSW. "Superposition coding and modulation technique for wireless relay systems." Awarded by:University of New South Wales, 2007. http://handle.unsw.edu.au/1959.4/36827.

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Cooperative communication has been considered a promising technique used in wireless network to introduce diversity. Based on distributed architecture, cooperative network enables single-antenna users to share their information as a virtual multiple antenna array, which makes it possible to enhance the user data rates and obtain the diversity gain. Depending on the ways users share and process the information, practical user cooperation is mainly grouped in three modes: Amplify and Forward (AF), Decode and Forward (DF) and Compress and Forward (CF). Generally, DF outperforms AF in most practical implementation and is alternately the best by theoretical analysis. In particular, it is shown in theory that DF outperforms CF when the inter-user link is in good condition and vice versa. Considered as a capacity achieving approach, superposition encoding technique produces approximate Gaussian output signals. It is the power and spectral efficiency of the encoding scheme that make it useful for several wireless communication systems such as MIMO system, relay channels, and so on. The main goal of the thesis is to study how much superposition coding can help when applied to DF user cooperation. In particular, a new DF scheme with soft information relaying technique is proposed to overcome the performance degradation happening when the quality of the inter-user channel is bad. Based on the scheme, soft log-likelihood ratio (LLR) of the relay decoder is quantized, encoded, modulated by superimposition and then forwarded to the destination. The destination receiver employs an iterative superposition decoder and modified maximum a posteriori probability (MAP) decoder to recover the transmitted signal from the source. The performance of the scheme is evaluated by simulation. We show that the new scheme can significantly outperform the conventional DF scheme even in a poor inter-user channel. Furthermore, a new cooperative transmission strategy based on superposition and multiuser detection techniques is also investigated in the thesis. The new scheme is an improved DF scheme in which the two users take turns in being the relay for each other and the signal forwarded by each user is the superimposed data of both users. Here, interleavers are introduced in the superposition process as an efficient user separation tool, providing a large improvement in error performance and also facilitating the decoding process at the destination. Different types of iterative receivers are examined. The performance of the scheme is evaluated by simulation. It is shown that the new transmission scheme outperforms the conventional one in terms of both spectral and power efficiency.

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Negi, Ansuya. "Analysis of Relay-based Cellular Systems." PDXScholar, 2006. https://pdxscholar.library.pdx.edu/open_access_etds/2668.

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Relays can be used in cellular systems to increase coverage as well as reduce the total power consumed by mobiles in a cell. This latter benefit is particularly useful for mobiles operating on a depleted battery. The relay can be a mobile, a car or any other device with the appropriate communication capabilities. In thesis we analyze the impact of using relays under different situations. We first consider the problem of reducing total power consumed in the system by employing relays intelligently. We find that in a simulated, fully random, mobile cellular network for CDMA (Code Division Multiple Access), significant energy savings are possible ranging from 1.76 dB to 8.45 dB. In addition to reducing power needs, relays can increase the coverage area of a cell by enabling mobiles located in dead spots to place relayed calls. We note that use of relays can increase the useful service area by about 10% with real life scenarios. We observe that in heavy building density areas there is more need of relays as compared to low building density areas. However, the chance of finding relays is greater in low building density areas. Indeed, having more available idle nodes helps in choosing relays, so we conclude that unlike present day implementations of cellular networks, the base station should admit more mobiles (beyond the capacity of the cell) even if they are not placing calls since they can be used as relays. One constraint of using relays is the potential to add interference in the same cell and in neighboring cells. This is particularly true if the relays are not under power control. Based on our analysis, we conclude that in interference limited systems like CDMA the relays have to be under power control otherwise we will reduce the total capacity by creating more dead spots. Thus, we believe that either the base station should be responsible to allocate relays or relays should be provided with enough intelligence to do power control of the downlink. Finally, we show how utility of data services can be increased by use of relays.

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Zhang, Jin. "Relay and routing selection in relay-based wireless networks /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?CSED%202009%20ZHANG.

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Zhang, Shunqing. "Cooperative relay in the next generation wireless networks /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?ECED%202009%20ZHANGS.

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Zhang, Jun. "Power control in wireless ad hoc networks /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?CSED%202007%20ZHANG.

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Kwon, Bongkyoung Kwon. "Adaptive frame structure and OFDMA resource allocation in mobile multi-hop relay networks." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31818.

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Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2010.
Committee Chair: Dr. John A. Copeland; Committee Member: Dr. George F. Riley; Committee Member: Dr. Henry L. Owen; Committee Member: Dr. Mary Ann Ingram; Committee Member: Dr. Patrick Traynor. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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Chen, Jiancong. "Mixed-mode wireless networks : framework and power control issues /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?COMP%202004%20CHEN.

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Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2004.
Includes bibliographical references (leaves 101-108). Also available in electronic version. Access restricted to campus users.

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Gylling, Marcus. "Remote wireless control of building management systems automation." Thesis, Blekinge Tekniska Högskola, Avdelningen för programvarusystem, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-5342.

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The controlling unit in building management system automation is a PLC. Every device in an installation is connected to the PLC. When a user wants to interact with a system an operator terminal, which is attached to a cabinet where the PLC is installed, is used. With this solution the user needs to be in front of the cabinet to interact with the system. Alarms do not get the user’s attention until the user checks the operator terminal. Using a solution where the communication with the PLC is done with a wireless interface would mean that the user interact with a system from a wider area. The solution should have the same functionality as today with the extension that the PLC should be able to contact the user if something is wrong in the installation. A PDA is used as a replacement for the operator terminal. This PDA uses two different techniques to communicate with the PLC. Bluetooth is used when the user is in the building and interacts with the system in a similar way to the operator terminals. GSM is used when the PLC needs to get the users attention by sending out alarms. With this solution the PDA can be used for several installations and thereby decrease cost. The project has turned out to be a success. The application that has been developed has improved a user’s interaction with a PLC.

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Jayasinghe, L. K. (Laddu Keeth Saliya). "Analysis on MIMO relaying scenarios in wireless communication systems." Doctoral thesis, Oulun yliopisto, 2015. http://urn.fi/urn:isbn:9789526207391.

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Abstract The thesis concentrates on evaluating and improving performances of various multiple-input multiple-output (MIMO) relaying scenarios that are particularly relevant to future wireless systems. A greater emphasis is placed on important practical situations, considering relay deployments, availability of channel state information (CSI), limitations of spectrum, and information secrecy. Initially, the performance of a non-coherent amplify-and-forward (AF) MIMO relaying is analyzed when the relay is deployed with the relay-to-destination channel having a line-of-sight (LoS) path. The main attention is given to analyzing the performance of orthogonal space-time block coded based non-coherent AF MIMO system. Exact expressions of statistical parameters and performance metrics are derived considering the instantaneous signal-to-noise ratio (SNR) received at the destination. These performance metrics reveal that a strong LoS component in relay-destination channel always limits the performance promised by MIMO scattering environment when both nodes have multiple antennas. The thesis also considers scenarios in MIMO two-way relaying (TWR) with physical layer network coding (PNC) mapping at the relay. PNC mapping becomes complex with multiple streams being combined at the relay node. Joint precoder-decoder schemes are considered to ease this, and various studies are carried out depending on the CSI. The zero-forcing criterion is used at the nodes when perfect CSI is available. For the imperfect CSI scenario, a robust joint precoder-decoder design is considered. The precoder and decoder matrices are obtained by solving optimization problems, which are formulated to maximize sum-rate and minimize weighted mean square error (WMSE) under transmit power constraints on the nodes. Next, a precoder-decoder scheme for MIMO underlay device-to-device (D2D) communication system is investigated by considering two D2D modes; PNC based D2D and direct D2D. The joint design is based on minimizing mean square error (MSE) which is useful to mitigate interference, and to improve the performance of both D2D and cellular communications. Distributed and centralized algorithms are proposed considering bi-directional communication in both D2D and cellular communications. System performance is discussed with two transmit mode selection schemes as dynamic and static selection schemes. The results show that the PNC based D2D mode extends the coverage area of D2D communication. Finally, secure beamforming schemes for the PNC based MIMO TWR systems are investigated when multiple eavesdroppers are attempting to intercept the user information. The CSI of the user-to-eavesdropper channels is imperfect at the users. The channel estimation errors are assumed with both ellipsoidal bound and Gaussian Markov uncertainty models. Robust optimization problems are formulated considering both scenarios to design beamforming vectors at the users and relay. Numerical results suggest that the proposed algorithms converge fast and provide higher security
Tiivistelmä Tässä väitöskirjassa keskitytään arvioimaan ja parantamaan suorituskykyä useissa moniantennitoistinjärjestelmissä, jotka ovat ajankohtaisia tulevaisuuden langattomissa verkoissa. Erityisesti työssä analysoidaan tärkeitä käytännön tilanteita, sisältäen toistimien sijoittamisen, kanavatiedon saatavuuden, rajoitetun taajuuskaistan ja tiedon salauksen. Aluksi epäkoherentin, vahvistavan ja jatkolähettävän moniantennitoistimen suorituskykyä analysoidaan tilanteessa, jossa toistin on sijoitettu siten, että kohteeseen on suora yhteys. Suorituskyvyn arvioinnin pääkohteena on ortogonaalinen tila-aika-tason lohkokoodattu epäkoherentti vahvistava ja jatkolähettävä moniantennitoistin. Työssä johdetaan tarkat lausekkeet tilastollisille parametreille ja suorituskykymittareille ottaen huomioon hetkellinen signaalikohinasuhde vastaanottimessa. Nämä suorituskykymittarit ilmaisevat, että toistimen ja kohteen välillä oleva vahva suoran yhteyden komponentti rajoittaa sitä suorituskykyä, jota moniantennijärjestelmän hajontaympäristö ennustaa. Työssä tutkitaan myös kahdensuuntaisia moniantennitoistimia, jotka käyttävät fyysisen kerroksen verkkokoodausta. Koodauksesta tulee monimutkaista, kun monia datavirtoja yhdistetään toistimessa. Tämän helpottamiseksi käytetään yhdistettyä esikoodaus-dekoodausmenetelmää, jota tutkitaan erilaisten kanavatietojen tapauksissa. Täydellisen kanavatiedon tapauksessa käytetään nollaanpakotuskriteeriä. Epätäydellisen kanavatiedon tapauksessa käytetään robustia yhdistettyä esikoodaus-dekoodausmenetelmää. Esikoodaus- ja dekoodausmatriisit saadaan ratkaisemalla optimointiongelmat. Nämä ongelmat on muodostettu maksimoimaan summadatanopeus, ja minimoimaan painotettu keskineliövirhe, kun optimointirajoitteina ovat solmujen lähetystehot. Seuraavaksi esikoodaus-dekoodausmenetelmää tutkitaan moniantennijärjestelmässä, jossa käytetään kahdentyyppistä laitteesta-laitteeseen (D2D) kommunikaatiomenetelmää: fyysisen kerroksen verkkokoodaukseen pohjautuvaa D2D- ja suoraa D2D-kommunikaatiota. Yhteissuunnittelu perustuu keskineliövirheen minimointiin, joka on hyödyllistä, kun halutaan vähentää häiriötä ja parantaa molempien verkkojen suorituskykyä. Työssä ehdotetaan hajautettuja ja keskitettyjä algoritmeja tilanteessa, jossa käytetään kaksisuuntaista kommunikaatiota molemmissa verkoissa. Järjestelmän suorituskykyä arvioidaan, kun käytetään kahta eri lähetystilan valintaa, dynaamista ja staattista. Tulokset osoittavat, että fyysisen kerroksen verkkokoodaukseen pohjautuva D2D kasvattaa D2D-kommunikaatiojärjestelmän kantamaa. Lopuksi, turvallisia keilanmuodostustekniikoita arvioidaan fyysisen kerroksen verkkokoodaukseen pohjautuvassa kahdensuuntaisessa moniantennitoistinjärjestelmässä, kun useat salakuuntelijat yritävät siepata käyttäjätiedon. Käyttäjillä on epäideaalinen kanavatieto heidän ja salakuuntelijoiden välisten linkkien kanavista. Kanavatiedon estimointivirheitä arvioidaan ellipsoidisella ja Gauss-Markov-epävarmuusmallilla. Robustit optimointiongelmat, joissa suunnitellaan keilanmuodostusvektorit käyttäjän ja toistimen välille, muodostetaan molemmille malleille. Numeeriset tulokset osoittavat, että ehdotetut algoritmit konvergoituvat nopeasti ja tarjoavat korkeamman turvallisuuden

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Xu, Ning. "Physical-Layer Network Coding for MIMO Systems." Thesis, University of North Texas, 2011. https://digital.library.unt.edu/ark:/67531/metadc68065/.

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The future wireless communication systems are required to meet the growing demands of reliability, bandwidth capacity, and mobility. However, as corruptions such as fading effects, thermal noise, are present in the channel, the occurrence of errors is unavoidable. Motivated by this, the work in this dissertation attempts to improve the system performance by way of exploiting schemes which statistically reduce the error rate, and in turn boost the system throughput. The network can be studied using a simplified model, the two-way relay channel, where two parties exchange messages via the assistance of a relay in between. In such scenarios, this dissertation performs theoretical analysis of the system, and derives closed-form and upper bound expressions of the error probability. These theoretical measurements are potentially helpful references for the practical system design. Additionally, several novel transmission methods including block relaying, permutation modulations for the physical-layer network coding, are proposed and discussed. Numerical simulation results are presented to support the validity of the conclusions.

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Dai, Gao Yang. "A novel soft forwarding technique for cooperative communication /." View abstract or full-text, 2010. http://library.ust.hk/cgi/db/thesis.pl?ECED%202010%20DAI.

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Patel, Chirag S. "Wireless channel modeling, simulation, and estimation." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-03282006-200818/.

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Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2006.
Andrew, Alfred, Committee Member ; Durgin, Gregory, Committee Member ; Li, Geoffrey, Committee Member ; Ingram, Mary Ann, Committee Member ; Stuber, Gordon, Committee Chair.

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Ho, Chi-Jui. "Call admission control in cellular networks." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/15730.

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Li, Bin. "Bandwidth allocation and call admission control in multi-services mobile wireless cellular networks /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202003%20LI.

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Pearce, David Andrew James. "Improving spectrum efficiency in fixed cellular communication systems." Thesis, University of York, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341520.

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Joe, Inwhee. "Error control for wireless ATM networks." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/15643.

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Choi, Gi Wan. "Low-complexity and power-efficient wireless cooperative relay networks with enhanced reliability." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47721.

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In recent years, global mobile data traffic has been increasing exponentially as mobile devices pervade our daily lives. To cope with the ever growing demands for higher data rates and seamless connectivity, one solution is to drastically increase the number of macro base stations in the conventional cellular architecture. However, this results in high deployment costs. Deploying low-power nodes such as relays that do not require a wired backhaul connection within a macrocell is one of cost-effective ways to extend high data rate coverage range. Relays are typically deployed to increase signal strength in poor coverage areas or to eliminate dead spots. But more importantly, relays provide a natural diversity, called cooperative diversity. In addition to a direct signal from a base station, extra copies of the same signal are forwarded from relays. Utilizing this diversity at the destination can yield significant performance enhancements. Thus, cooperative relay strategies need to be considered to enable high data rate coverage in a cost-effective manner. In this dissertation, we consider a simple single-relay network and present low-complexity and power-efficient cooperative relay designs that can achieve low error rate. We first study decode-and-forward (DF) relay networks with a single antenna at each node, where the relay decodes the received signal and forwards the re-encoded information to the destination. In DF relay scheme, decoding at the relay is not perfect and the error-propagation phenomenon is a detrimental problem, preventing the destination from collecting the cooperative diversity. To enable cooperative diversity in DF relay networks, we adopt link-adaptive power-scaling relay strategies where the relay scales the transmission power of the re-encoded signal based on the reliability of the source-relay link. We generalize power-profile designs and analyze the diversity order enabled by the general power-profile designs. We provide necessary and sufficient conditions for the designs to enable full cooperative diversity at the destination. In the second part of this dissertation, we extend the power-scaling relay strategy to DF multi-input multi-output (MIMO) relay networks, where multiple antennas are adopted at each node, and show that full cooperative diversity can also be achieved here. To collect spatial diversity provided by multiple antennas without using maximum-likelihood equalizers (MLEs) or near-ML detectors which exhibit high complexity, channel-controlled automatic repeat request (CC-ARQ) scheme is developed for DF MIMO relay networks to enable spatial diversity with linear equalizers (LEs) maintaining low-complexity. We also show that joint cooperative and spatial diversity can be achieved at the destination when the power-scaling strategy and the CC-ARQ with LEs are combined. Finally, amplify-and-forward (AF) MIMO relay designs, where the relay simply amplifies the received signal and forwards it to the destination, are studied with consideration of peak-power constraints at the relay. One practical concern for AF relaying is that the output signal at the relay may suffer from large peak-to-average power ratio (PAR), which may cause nonlinear distortion and/or saturation in the transmitted signal due to the limited linear range of power amplifiers. Thus, we first investigate peak-power constrained power-scaling strategies and find a sufficient condition to enable joint cooperative and spatial diversity at the destination. Based on this study, we propose simple and practical AF MIMO relay designs with peak-power constraint at the relay. CC-ARQ is also applied to AF MIMO relay networks to reduce the decoding complexity.

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Wang, Baobing. "Topology control and channel assignment in wireless multi-hop networks /." access full-text access abstract and table of contents, 2009. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?mphil-cs-b2375087xf.pdf.

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Thesis (M.Phil.)--City University of Hong Kong, 2009.
"Submitted to Department of Computer Science in partial fulfillment of the requirements for the degree of Master of Philosophy." Includes bibliographical references (leaves 60-64)

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Cardoso, de Castro Nicolas. "Energy-aware control and communication co-design in wireless net-worked control systems." Thesis, Grenoble, 2012. http://www.theses.fr/2012GRENT113/document.

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L'énergie est une ressource clé dans les systèmes commandés en réseau, en particulier dans les applications concernant les réseaux sans fil. Cette thèse étudie comment économiser l'énergie dans les capteurs sans fil avec une co-Conception contrôle et communication. Cette thèse examine les techniques et les approches existantes qui sont utilisées pour économiser l'énergie d'un point de vue de la communication et du contrôle. Cet étude est organisée selon une architecture de communication par couches couvrant de bas en haut les couches Physique, Liaison, Réseau, et Application. Puis, à partir de la conclusion que la puce radio est un important consommateur d'énergie, une loi conjointe de gestion des modes radio et de contrôle en boucle fermée est établie. La gestion des modes radio exploite les capacités de la puce radio à communter dans des modes de basses consommation pour économiser l'énergie, et d'adapter la puissance de transmission aux conditions du canal. Il en résulte un système de contrôle basé sur des événements où le système fonctionne en boucle ouverte à certains moments. Un compromis naturel apparaît entre l'économie d'énergie et les performances de contrôle. La loi conjointe est établie avec une formulation de contrôle optimal utilisant la Programmation Dynamique. Cette thèse résout le problème optimal dans les deux cas d'horizon infini et fini. La stabilité du système en boucle fermée est étudiée avec la formulation Input-To-State Stability (ISS). La principale conclusion de cette thèse, également illustrée dans la simulation, est que la conception à travers différentes couches dans les systèmes commandés en réseau est essentielle pour économiser l'énergie dans les noeuds sans fil
Energy is a key resource in Networked Control Systems, in particular in applications concerning wireless networks. This thesis investigates how to save energy in wireless sensor nodes with control and communication co-Design. This thesis reviews existing techniques and approaches that are used to save energy from a communication and a control point of view. This review is organized according to the layered communication architecture covering from bottom to top the Physical, Data Link, Network, and Application layers. Then, from the conclusion that the radio chip is an important energy consumer, a joint radio-Mode management and feedback law policy is derived. The radio-Mode management exploits the capabilities of the radio chip to switch to low consuming radio-Modes to save energy, and to adapt the transmission power to the channel conditions. This results in an event-Based control scheme where the system runs open loop at certain time. A natural trade-Off appears between energy savings and control performance. The joint policy is derived in the framework of Optimal Control with the use of Dynamic Programming. This thesis solves the optimal problem in both infinite and finite horizon cases. Stability of the closed loop system is investigated with Input-To-State Stability framework. The main conclusion of this thesis, also shown in simulation, is that cross-Layer design in Networked Control System is essential to save energy in the wireless nodes

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Yackoski, Justin. "High performance medium access control protocols for decentralized wireless networks using local coordination." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 156 p, 2009. http://proquest.umi.com/pqdweb?did=1833647411&sid=1&Fmt=2&clientId=8331&RQT=309&VName=PQD.

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Shen, Ji. "Efficient 3G multimedia communication control protocol (H.245) and implementations /." access full-text access abstract and table of contents, 2005. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?mphil-cs-b19886093a.pdf.

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Thesis (M.Phil.)--City University of Hong Kong, 2005.
"Submitted to Department of Computer Science in partial fulfillment of the requirements for the degree of Master of Philosophy" Includes bibliographical references (leaves 110-112)

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Kohagura, Monique Sachie. "Local coordination medium access control for wireless sensor networks." Online access for everyone, 2008. http://www.dissertations.wsu.edu/Thesis/Summer2008/m_kohagura_050808.pdf.

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梁鉅輝 and Kui-fai Leung. "Enhancing transmission control protocol performance over wireless networks." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31227570.

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Javali, Nagesh. "Topology control for wireless ad-hoc networks." Click here for download, 2008. http://proquest.umi.com/pqdweb?did=1580780361&sid=1&Fmt=2&clientId=3260&RQT=309&VName=PQD.

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Thesis (M.S.)--Villanova University, 2008.
"This research work is funded in part by National Science Foundation (NSF), Computing and Communication Foundation (CCF) award 0728909"--P. iii. Computer Science Dept. Includes bibliographical references.

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Ma, Jun. "Channel estimation and signal detection for wireless relay." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37082.

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Wireless relay can be utilized to extend signal coverage, achieve spatial diversity by user cooperation, or shield mobile terminals from adverse channel conditions over the direct link. In a two-hop multi-input-multi-output (MIMO) amplify-and-forward (AF) relay system, the overall noise at the destination station (DS) consists of the colored noise forwarded from the relay station (RS) and the local white noise. We propose blind noise correlation estimation at the DS by utilizing statistics of the broadband relay channel over the RS-DS hop, which effectively improves signal detection at the DS. For further performance improvement, we also propose to estimate the two cascaded MIMO relay channels over the source-RS and the RS-DS links at the DS based on the overall channel between the source and the DS and the amplifying matrix applied at the RS. To cancel cross-talk interference at a channel-reuse-relay-station (CRRS), we utilize the random forwarded signals of the CRRS as equivalent pilots for local coupling channel estimation and achieve a much higher post signal-to-interference ratio (SIR) than the conventional dedicated pilots assisted cancellers without causing any in-band interference at the DS. When an OFDM-based RS is deployed on a high-speed train to shield mobile terminals from the high Doppler frequency over the direct link, inter-subchannel interference (ICI) mitigation is required at the RS. By utilizing statistics of the channel between the base station and the train, we develop both full-rate and reduced-rate OFDM transmission with inherent ICI self-cancellation via transmit and/or receive preprocessing, which achieve significant performance improvement over the existing ICI self-cancellation schemes.

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Hoang, Le-Nam. "Relaying for Timely and Reliable Message Dissemination in Wireless Distributed Control Systems." Licentiate thesis, Högskolan i Halmstad, Centrum för forskning om inbyggda system (CERES), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-28245.

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Distributed control applications enabled by wireless networks are becoming more and more frequent. The advantages of wireless access are many, as control systems become mobile, autonomous and connected. Examples include platooning and automated factories. However, distributed control systems have stringent requirement on both reliability and timeliness, the latter in terms of deadlines. If the deadline is missed, the packet is considered useless, similarly to a lost or erroneous packet in a system without deadlines. In addition, wireless channels are, by nature, more exposed to noise and interference than their wired counterparts. Consequently, it implies a considerable challenge to fulfill the deadline requirements with sufficient reliability for proper functionality of distributed control applications. However, by taking advantage of cooperative communications, increased reliability can be achieved with little or no additional delay. Reducing the delay until a message is successfully received is a two-fold problem: providing channel access with a predictable maximum delay and maximizing the reliability of each transmission, once granted by the medium access method. To this end, this thesis proposes a framework that provides a bounded channel access delay and handles the co-existence of both time-triggered and event-driven messages encountered in distributed control applications. In addition, the thesis proposes and evaluates an efficient message dissemination technique based on relaying that maximizes the reliability given a certain deadline, or alternatively determines the delay required to achieve a certain reliability threshold for both unicast and broadcast scenarios. Numerical results, which are verified by Monte-Carlo simulations, show significant improvements with the proposed relaying scheme as compared to a conventional scheme without cooperation, providing more reliable message delivery given a fixed number of available time-slots. It also becomes clear in which situations relaying is preferable and in which situations pure retransmissions are preferable, as the relay selection algorithm will always pick the best option. The relay selection algorithm has a reasonable complexity and can be used by both routing algorithms and relaying scenarios in any time-critical application as long as it is used together with a framework that enables predictable channel access. In addition, it can be implemented on top of commercially available transceivers.
ACDC

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31

Clark, Jeffrey S. "Noise attenuation and communication enhancement characteristics of the USCG boat crew communication system." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5675.

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Thesis (M.S.)--West Virginia University, 2008.
Title from document title page. Document formatted into pages; contains iv, 44 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 36-37).

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Kang, Intae. "Topology control for broadcasting over energy constrained wireless ad hoc networks /." Thesis, Connect to this title online; UW restricted, 2005. http://hdl.handle.net/1773/6061.

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Fu, Shengli. "Space-time coding and decoding for MIMO wireless communication systems." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 0.57Mb, 156 p, 2005. http://wwwlib.umi.com/dissertations/fullcit?3182631.

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34

Khan, Nabeel Pervaiz. "Energy efficient communication and rate control algorithms for wireless sensor networks." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 114 p, 2009. http://proquest.umi.com/pqdweb?did=1818417511&sid=4&Fmt=2&clientId=8331&RQT=309&VName=PQD.

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35

Yankopolus, Andreas George. "Adaptive Error Control for Wireless Multimedia." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5237.

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Future wireless networks will be required to support multimedia traffic in addition to traditional best-effort network services. Supporting multimedia traffic on wired networks presents a large number of design problems, particularly for networks that run connectionless data transport protocols such as the TCP/IP protocol suite. These problems are magnified for wireless links, as the quality of such links varies widely and uncontrollably. This dissertation presents new tools developed for the design and realization of wireless networks including, for the first time, analytical channel models for predicting the efficacy of error control codes, interleaving schemes, and signalling protocols, and several novel algorithms for matching and adapting system parameters (such as error control and frame length) to time-varying channels and Quality of Service (QoS) requirements.

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36

Raad, Raad. "Neuro-fuzzy admission control in mobile communications systems." Access electronically, 2005. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20061030.153500/index.html.

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37

Levine, David A. "Resource allocation, call admission, and media access control protocols for wireless multimedia networks." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/14766.

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38

XU, YONG. "RESOURCE MANAGEMENT AND QoS CONTROL IN MULTIPLE TRAFFIC WIRELESS AND MOBILE COMMUNICATION SYSTEMS." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1132017118.

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39

Kirsch, Nicholas J. Dandekar Kapil. "Experimental analysis of power control and element spacing for unobtrusive MIMO antenna systems /." Philadelphia, Pa. : Drexel University, 2009. http://hdl.handle.net/1860/3072.

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40

Carter, Clinton E. "Susceptibility of a digital turbine control system to IEEE 802.11 compliant emissions." Thesis, University of North Texas, 2003. https://digital.library.unt.edu/ark:/67531/metadc4433/.

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Within the nuclear industry, there have been numerous instances of radio transmissions interfering with sensitive plant equipment. Instances documented vary from minor instrument fluctuations to major plant transients including reactor trips. With the nuclear power industry moving toward digital technologies for control and reactor protection systems, concern exists regarding their potential susceptibility to contemporary wireless telecommunications technologies. This study evaluates the susceptibility of Comanche Peak's planned turbine controls upgrade to IEEE 802.11 compliant wireless radio emissions. The study includes a review of previous research, industry emissions standards, and technical overview of the various IEEE 802.11 protocols and details the testing methodology utilized to evaluate the digital control system. The results of this study concluded that the subject digital control system was unaffected by IEEE 802.11 compliant emissions even when the transmitter was in direct contact with sensitive components.

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Liu, Yunhuai. "Probabilistic topology control in wireless sensor networks /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?CSED%202008%20LIU.

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42

Yu, Sam Shaokai. "Performance analysis and call control procedures in high-speed multimedia personal wireless communications /." Title page, abstract and contents only, 1999. http://web4.library.adelaide.edu.au/theses/09PH/09phy936.pdf.

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43

Suh, Robert J. "Wireless content repurposing architecture for DC command and control." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03sep%5FSuh.pdf.

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Thesis (M.S. in Systems Engineering)--Naval Postgraduate School, September 2003.
Thesis advisor(s): Gurminder Singh, Perry McDowell. Includes bibliographical references (p. 55-56). Also available online.

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44

Lai, Chengdi, and 赖成迪. "Congestion control for transmission control protocol (TCP) in wirelessnetworks." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47102445.

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The best MPhil thesis in the Faculties of Dentistry, Engineering, Medicine and Science (University of Hong Kong), Li Ka Shing Prize,2010-11.
published_or_final_version
Electrical and Electronic Engineering
Master
Master of Philosophy

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45

Yin, Bolian. "Adaptive clustering and transmission range adjustment for topology control in wireless sensor networks." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4485.

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Thesis (Ph. D.) University of Missouri-Columbia, 2006.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 10, 2007) Vita. Includes bibliographical references.

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46

Huang, Yan-Yu. "CMOS-based amplitude and phase control circuits designed for multi-standard wireless communication systems." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/44908.

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Designing CMOS linear transmitter front-end, specially the power amplifiers (PAs), in multi-band wireless transceivers is a major challenge for the single-chip integration of a CMOS radio. In some of the linear PA systems, for example, polar- or predistortion-PA system, amplitude and phase control circuits are used to suppress the distortion produces by the PA core. The requirements of these controlling circuits are much different from their conventional role in a receiver or a phase array system. In this dissertation, the special design issues will be addressed, and the circuit topologies of the amplitude and phase controllers will be proposed. In attempt to control the high-power input signal of a PA system, a highly linear variable attenuator with adaptive body biasing is first introduced. The voltage swing on the signal path is intentionally coupled to the body terminal of the triple-well NMOS devices to reduce their impedance variation. The fabricated variable attenuator shows a significant improvement on linearity as compared to previous CMOS works. The results of this research are then used to build a variable gain amplifier for linear PA systems that requires gain of its amplitude tuning circuits. Different from the conventional attenuator-based VGAs, the high linearity of the suggested attenuator allows it to be put after the gain stage in the presented VGA topology. This arrangement along with the current boosting technique gives the VGA a better noise performance while having a linear-in-dB tuning curve and better worst-case linearity. The following part of the dissertation is about a compact, linear-in-degree tuned variable phase shifter as the phase controller in the PA system. This design uses a modified RC poly-phase filter to produce a set of an orthogonal phase vectors with smaller loss. A specially designed control circuit combines these vectors and generates an output signal with different phases, while having very small gain mismatches at different phase setting. The proposed amplitude and phase control circuits are then verified with a system level analysis. The results show that the proposed designs successfully reduce the non-linear effect of a wireless transmitter.

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47

Möller, Anders. "Modeling and Stability Analysis of Rate and Power Control Systems in Wireless Communication Networks." Doctoral thesis, KTH, Optimeringslära och systemteori, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-93222.

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Wireless data traffic in cellular networks is currently undergoing a strong global expansion and the demand for high and reliable data throughput increases. Capacity is, however, a limited resource, and in radio resource management a trade-off has to be made between the congestion level, related to cell coverage and interference levels, and the Quality of Service (QoS) or data rates of the users. The radio channel conditions vary on a fast time scale and the measurements of the received signals are subject to disturbances and uncertainties. This motivates the use of control strategies to update the transmission powers. In fact, in implementations of uplink in cellular networks, the performance of the network is ensured by using a fast inner power control algorithm to track a QoS-target and a slower outer control algorithm to limit congestion. Several theoretical challenges arise in this problem setting. Due to the nature of the network, both information and control are distributed. Furthermore, measurements of the congestion and the QoS are used in the control loops, which introduces nonlinear feedback. Another complicating factor is that filtering, computations and information exchange in the network cause time-delays and dynamics. In this thesis we address these challenges by using modeling and analysis tools in systems and control. The objective is to provide systematic methods to quantify the fundamental limitations of the system and to point out the trade-offs for a given system design. We perform stability analysis on a high mathematical level that provides results that are simple to compute and that reveal the system structure. In Paper A we extend existing power control models and stability frameworks to include dynamics. For this we use a general definition of the interference. Moreover, stability is addressed by a monotonicity approach and by proposing a Lyapunov function. Paper B provides less conservative stability results using input-output analysis for the same system model. Stability of a linearization of the system model is studied in Paper C with the multivariate Nyquist criterion. Moreover, we use discrete multivariate describing functions to analyze the equilibrium oscillations that arise due to binary feedback. In Paper D we extend the model with an outer control loop, which dynamically sets the reference value to the control algorithm studied in Papers A to C. The main analysis tool for stability is input-output theory.

QC 201204013

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48

Rajashekharaiah, Mallesh. "Gain control and linearity improvement for low noise amplifiers in 5GHZ direct conversion receivers." Online access for everyone, 2005. http://www.dissertations.wsu.edu/Thesis/Spring2005/m%5Frajashekharaiah%5F050405.pdf.

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49

Hassan, Ahmed Mohamed Ali Omer. "Topology control in wireless ad hoc networks." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86709.

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Thesis (MSc)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: Wireless ad hoc networks are increasingly used in today’s life in various areas ranging from environmental monitoring to the military. For technical reasons, they are severely limited in terms of battery power, communication capacity and computation capability. Research has been carried out to deal with these limitations using different approaches. A theoretical treatment of the subject is topology control whose basic task is to design network topologies with special properties that make them energy-efficient and interference-optimal. We study, implement and compare the XTC and CBTC algorithms in terms of interference reduction, length stretch factor and maximum degree. These two algorithms have two features that are absent in almost all competitive topology control algorithms which are practicality and maintaining connectivity. Both algorithms show good performance in terms of interference reduction and maintaining a good length stretch factor. Regarding CBTC, we prove that it is a power spanner. We show through extensive simulation that the degree distribution of wireless ad hoc networks modelled by the log-normal model is binomial if the average degree is not high. We find that there is no fixed threshold for the average degree at which the distribution is distorted and no longer binomial. We show through simulation that the node density which ensures the absence of isolated nodes is a tight lower bound for the node density which ensures connectivity. The implication of this result is that connectivity is ensured with high probability if the minimum node degree is equal to 1. Finally we show through simulation that the log-normal model is not a realistic representation of wireless ad hoc networks if the environmental parameter is at least 6. This result is important because there are no available measurements to determine the range of the environmental parameter for typical frequencies used in wireless ad hoc networks.
AFRIKAANSE OPSOMMING: Koordlose ad hoc netwerke word toenemend gebruik in vandag se lewe op verskillende gebiede wat wissel van die omgewing monitor tot militêregebruik. Vir tegniese redes is hulle ernstig beperk in terme van battery krag, kommunikasie kapasiteit en berekeningsvermoë. Navorsing vanuit verkillende benaderings word gedoen om met hierdie beperkings te deel. ’n Teoretiese benadering tot onderwerp is topologie beheer. Die basiese taak is om netwerktopologieë met spesiale eienskappe wat hulle energie-doeltreffend en interferensieoptimaal maak te ontwerp. Ons bestudeer, implementeer en vergelyk die XTC en CBTC algoritmes in terme van interferensie vermindering, lengte rek faktor en maksimum graad. Beide hierdie algoritmes het twee eienskappe wat afwesig is in byna al die mededingende topologie beheer algoritmes: hulle is prakties en handhaf verbindings. Beide algoritmes toon goeie prestasie in terme van interferensie verminder en die handhawing van ’n goeie lengte rek faktor. Ten opsigte van CBTC bewys ons dat dit ’n “power spanner” is. Ons wys deur middel van uitgebreide simulasie dat die graad verdeling van die koordlose ad hoc netwerke wat deur die log-normale model gemodelleer kan word binomiaal is as die gemiddelde graad nie hoog is nie. Ons vind dat daar geen vaste drempel is vir die gemiddelde graad waarby die verdeling vervorm en nie meer binomiaal is nie. Ons wys deur simulasie dat die node digtheid wat die afwesigheid van geïsoleerde nodusse verseker ’n streng ondergrens vir die node digtheid wat konnektiviteit verseker is. Die implikasie van hierdie resultaat is dat ‘n konneksie verseker word as die minimum node graad gelyk is aan 1. Ten slotte wys ons deur simulasie dat die log-normale model nie ’n realistiese voorstelling van koordlose ad hoc netwerke is wanneer die “environmental parameter” groter is as 6 nie. Hierdie resultaat is belangrik, want daar is geen beskikbare metings om die grense van hierdie parameter vir ’n tipiese frekwensie gebruik in koordlose ad hoc netwerke te bepaal nie.

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Yuan, Yin. "Transmission power control in wireless ad-hoc networks /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?ECED%202008%20YUAN.

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Dissertations / Theses on the topic 'Wireless communication systems Relay control systems'

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