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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Co-primary multi-operator resource sharing for small cell networks

Luoto, P. (Petri) 06 March 2017 (has links)
Abstract The aim of this thesis is to devise novel co-primary spectrum sharing (CoPSS) methods for future fifth generation (5G) networks and beyond. The target is to improve data rates of small cell networks (SCNs) in which mobile network operators (MNOs) share their dedicated frequency spectrum (spectrum pooling) or a common spectrum (mutual renting). The performance of the proposed methods is assessed through extensive system-level simulations. MNOs typically acquire exclusive usage rights for certain frequency bands and have little incentive to share spectrums with other operators. However, due to higher cost and spectrum scarcity at lower frequencies it is expected that efficient use of the spectrum in 5G networks will rely more on spectrum sharing than exclusive licenses. This is especially true for new higher candidate frequencies (> 6 GHz) that do not have a pre-existing spectrum regulation framework. In the first part of the thesis, we tackle the challenge of providing higher data rates within limited spectral resources. Each SCN MNO has its own dedicated spectrum, and each MNO defines a percentage of how much its spectrum it is willing to share. The idea of the proposed CoPSS algorithms is that the spectrum is dynamically shared among MNOs based on their spectrum utilization, which is shared among MNOs in the network. This way interference can be avoided and spectrum utilization is maximized. Unused resources are shared equally between overloaded MNOs for a given time instant. Thus, only short-term fairness among overloaded SCNs can be guaranteed. In the second part, we consider a multi-operator small cell network where MNOs share a common pool of radio resources. The goal is to ensure the long term fairness of spectrum sharing without coordination among small cell base stations. We develop a decentralized control mechanism for base stations using the Gibbs sampling based learning tool, which allocates suitable amount of the spectrum for each base station while avoiding interference from SCNs and maximizing the total network throughput. In the studied scenarios, we show the importance of coordination among MNOs when the dedicated spectrum is shared. However, when MNOs share a common spectrum, a decentralized control mechanism can be used to allocate suitable amounts of spectrum for each base station. The proposed algorithms are shown to be effective for different network layouts, by achieving significant data rate enhancements with a low overhead. / Tiivistelmä Tämä väitöskirja keskittyy kehittämään uusia menetelmiä, joilla jaetaan taajuuksia useiden operaattoreiden kesken tulevista viidennen sukupolven verkoista alkaen. Päätavoite on parantaa tiedonsiirtonopeuksia sellaisissa piensoluverkoissa, joissa matkapuhelinoperaattorit jakavat joko heidän omia taajuusalueitaan tai heillä yhteisomistuksessa olevia taajuuksia. Kehitettyjen menetelmien suorituskykyä arvioidaan mittavien järjestelmätason simulointien avulla. Matkapuhelinoperaattorit tyypillisesti omistavat yksin tietyt taajuusalueet, eivätkä ole valmiita jakamaan niitä. On kuitenkin oletettu, että tulevaisuudessa matkapuhelinoperaattorit joutuvat jakamaan taajuuksia, koska taajuusalueet ovat kalliita ja niukkoja erityisesti matalilla taajuusalueilla. Korkeammat taajuusalueet (> 6 GHz) puolestaan muodostavat otollisen alustan tehokkaalle spektrin jaetulle käytölle, koska niillä ei ole vielä olemassa olevaa taajuussääntelyä. Väitöskirjan ensimmäisessä osassa keskitytään kasvattamaan tiedonsiirtonopeuksia kun jokainen matkapuhelinoperaattori omistaa oman taajuuskaistansa ja matkapuhelinoperaattorit määrittävät kuinka suuren prosentuaalisen osuuden ovat valmiita jakamaan. Esitettyjen algoritmien päätavoite on jakaa taajuuksia dynaamisesti matkapuhelinoperaattoreiden kesken. Algoritmeissa hyödynnetään tietoa matkapuhelinoperaattoreiden taajuuden käyttöasteesta, jonka matkapuhelinoperaattoritkommunikoivat toisilleen. Näin häiriö voidaan välttää ja taajuuden käyttö maksimoidaan. Käyttämättömät taajuudet jaetaan tasaisesti matkapuhelinoperaattorien kesken tietyllä ajanhetkellä. Näin voidaan taata lyhytaikainen oikeudenmukainen taajuuksien käyttö, mutta ei pitkäaikaista oikeudenmukaista taajuuksien käyttöä. Väitöskirjan toisessa osassa matkapuhelinoperaattorit jakavat yhteisomistuksessa olevia taajuuksia. Tavoitteena on saavuttaa pitkäaikainen taajuuksien oikeudenmukainen käyttö, kun piensoluverkot eivät kommunikoi keskenään. Työssä kehitetään piensoluverkoille hajautettu algoritmi, joka perustuu oppimistyökaluun Gibbs-näytteistys. Näin saadaan allokoitua jokaiselle tukiasemalle tarvittava määrä taajuusresursseja niin, että häiriö tukiasemien välillä minimoidaan ja koko piensoluverkon suorituskyky maksimoidaan. Tutkituissa skenaarioissa osoitetaan matkapuhelinoperaattoreiden välisen koordinaation tärkeys, kun jaetaan omia taajuusalueita. Toisaalta kun operaattorit jakavat yhteisomistuksessa olevia taajuuksia on mahdollista käyttää algoritmeja, joissa ei ole koordinaatiota matkapuhelinoperaattoreiden kesken. Väitöskirjassa vahvistetaan kehitettyjen algoritmien olevan tehokkaita ja sopivan monenlaisiin verkkoympäristöihin saavuttaen merkittäviä parannuksia tiedonsiirtonopeuteen ilman suuria kustannuksia.
2

Ordnungsreduktion von elektrostatisch-mechanischen Finite Elemente Modellen für die Mikrosystemtechnik

Bennini, Fouad 07 October 2005 (has links) (PDF)
In der vorliegenden Arbeit wird eine Prozedur zur Ordnungsreduktion von Finite Elemente Modellen mikromechanischer Struktur mit elektrostatischem Wirkprinzip entwickelt und analysiert. Hintergrund der Ordnungsreduktion ist eine Koordinatentransformation von lokalen Finite Elemente Koordinaten in globale Koordinaten. Die globalen Koordinaten des reduzierten Modells werden durch einige wenige Formfunktionen beschrieben. Damit wird das Makromodell nicht mehr durch lokale Knotenverschiebungen beschrieben, sondern durch globale Formfunktionen, welche die gesamte Deformation der Struktur beeinflussen. Es wird gezeigt, dass Eigenvektoren der linearisierten mechanischen Struktur einfache und effiziente Formfunktionen darstellen. Weiterhin kann diese Methode für bestimmte Nichtlinearitäten und für verschiedene in Mikrosystemen auftretende Lasten angewendet werden. Das Ergebnis sind Makromodelle, die über Klemmen in Systemsimulatoren eingebunden werden können, die Genauigkeiten einer Finite Elemente Analyse erreichen und für Systemsimulationen typische Laufzeitverhalten besitzen.
3

3GPP Long Term Evolution: Performance Analysis and Evolution towards 4G with Coordinated Multi-Point Transmission

Martín-Sacristán Gandía, David 02 May 2016 (has links)
[EN] In today's information society, there is a growing need to access data communication services ubiquitously, with mobility and increasingly higher data rates. This society's demand has motivated the development of the fourth generation of mobile communications (4G) and its evolution towards the fifth generation (5G). This development has required a revolution on the radio interface of the mobile communications systems, and, consequently, has significantly modified their capabilities and their radio resource management. This is the case of the technology known as Long Term Evolution (LTE) and its 4G version called LTE-Advanced. This Doctoral Thesis addresses the modelling, the radio resource management analysis, and the performance evaluation of the downlink of LTE and LTE-Advanced where, among the different features of LTE-Advanced, the focus is on the Coordinated Multi-Point (CoMP) transmission. The Thesis provides a detailed description of the main characteristics of LTE and LTE-Advanced. The high complexity of these systems, has prompted the use of computer simulations as the primary research methodology. The Thesis makes a detailed description of the simulation methodology and the system modelling required, including some contributions of the author in this field. Among them, it is of significant relevance the link-level simulation results used in the European project WINNER + for the LTE evaluation. With regard to the analysis of the radio resource management in LTE, the fundamentals of link adaptation and scheduling are explained in the first place. In relation to the scheduling, the Thesis includes a thorough study of the proportional fairness concept and the suboptimal implementation typically used in LTE to maximize this metric. This study has resulted in a series of ideas embodied in a modification of the typical implementation, which has proved to be capable of increasing the proportional fairness of the resource allocations. Moreover, the link adaptation analysis has revealed the "flash-light" effect problem, which is characterized by a high interference variability due to rapid changes in the scheduling decisions. The Thesis demonstrates that a particular implementation that stabilizes the scheduling decisions can improve the system performance. The radio resource management analysis of this Thesis is completed with the study of CoMP. Specifically, the CoMP scheme studied in this Thesis is a solution with coordinated scheduling and beamforming (CS/CB), that takes into account realistic and robust assumptions concerning the knowledge that the coordinated points have about the channel state. The Thesis proposes this solution for its simplicity and its ability to improve high data rates coverage and capacity even with incomplete channel knowledge. Concerning LTE and LTE-Advanced evaluation, it is performed in two different types of scenarios. On the one hand, the scenarios defined in the process of evaluation of IMT-Advanced. In this framework, it is evaluated the importance of different multi-antenna techniques, including CoMP, considering full-buffer traffic models. The most important conclusions in these scenarios are the significant performance improvement achieved with spatial multiplexing of users and the fact that CoMP mechanisms provide a reduced benefit. The second group of scenarios are those defined by the European project METIS for the evaluation of 5G technologies. Specifically, an indoor office scenario and an outdoor sports stadium have been selected. In these scenarios, a realistic traffic model is used, and it has been demonstrated the utility of CoMP to satisfy the first 5G requirement definitions with feasible frequency bandwidths. In these scenarios with less homogeneous deployments, or with a limited number of transmitters originating the major part of interference, is where this Thesis has found CoMP to be more useful and where the Thesis promotes its use. / [ES] En la actual sociedad, hay una creciente necesidad de acceso a servicios de comunicación de datos de forma ubicua, móvil y a velocidades cada vez más altas. Esta demanda ha motivado el desarrollo de la cuarta generación de comunicaciones móviles (4G) y su evolución hacia la quinta generación (5G). Este desarrollo ha requerido una revolución en la interfaz radio de los sistemas de comunicaciones móviles modificando en gran medida sus capacidades y la forma en la que se gestionan sus recursos. Este es el caso de la tecnología conocida como Long Term Evolution (LTE) y su versión 4G llamada LTE-Advanced. En concreto, esta Tesis Doctoral aborda el modelado, análisis de la gestión de recursos radio y evaluación de prestaciones del enlace descendente de LTE y LTE-Advanced, donde, de entre las características de LTE-Advanced, se ha puesto el foco de atención en la transmisión multipunto coordinada (CoMP). La Tesis proporciona una descripción detallada de las principales características de LTE y LTE-Advanced. La gran complejidad del sistema descrito ha motivado que la metodología de estudio haya sido la simulación mediante ordenador. La Tesis realiza una descripción detallada de dicha metodología y del modelado del sistema empleado, incluyendo algunas aportaciones del autor en este campo. De entre éstas, destaca la provisión de resultados de simulación de nivel de enlace que se usaron en el proyecto europeo WINNER+ para la evaluación de LTE. En cuanto al análisis de la gestión de recursos radio en LTE, en primer lugar, se explican los fundamentos de la adaptación al enlace y el scheduling. En relación con el scheduling, se realiza un estudio del concepto de proportional fairness y de la implementación subóptima típicamente usada en LTE para maximizar esta métrica. Este estudio ha dado como resultado una modificación de la implementación típica que ha demostrado ser capaz de aumentar la proportional fairness en la asignación de recursos con un bajo incremento de complejidad. Además, el análisis de la adaptación al enlace ha revelado el problema del efecto de "luz de flash" consistente en la alta variabilidad de la interferencia debida a rápidos cambios en las decisiones del scheduler. La Tesis demuestra que se pueden mejorar las prestaciones del sistema estabilizando dichas decisiones mediante una implementación concreta. El bloque de análisis de la gestión de recursos se completa con el estudio de CoMP. Específicamente, se estudia una solución con coordinación de scheduling y conformación de haz (CS/CB) que tiene en cuenta suposiciones reales y robustas en cuanto al conocimiento que los puntos coordinados tienen de los canales radio. La Tesis propone esta solución por su sencillez y capacidad de mejorar la eficiencia de los sistemas de comunicaciones móviles, tanto en cobertura de velocidades altas de transmisión como en capacidad, aun teniendo un conocimiento incompleto del canal. En cuanto a la evaluación de LTE y LTE-Advanced, ésta se realiza en dos tipos de escenarios. Por un lado, los escenarios definidos en el proceso de evaluación de IMT-Advanced. En este marco, se evalúa la importancia de diferentes técnicas de transmisión multiantena, incluyendo CoMP, y considerando tráfico de tipo full-buffer. Se ha obtenido una gran mejora de prestaciones por la multiplexación espacial de usuarios y mejoras discretas por el uso de CoMP. El segundo grupo de escenarios son los definidos por el proyecto europeo METIS para evaluación de tecnologías 5G, concretamente se han elegido un escenario de interiores con una oficina, y uno de exteriores con un estadio deportivo. En estos escenarios se utiliza un tráfico realista y se ha demostrado la utilidad de CoMP para mejorar las prestaciones del sistema. En estos escenarios con despliegues menos uniformes, o con un número limitado de transmisores provocando la mayor parte de la interferencia, es donde esta Tesis ha encontrado la mayor u / [CAT] En l'actual societat de la informació, hi ha una creixent necessitat d'accés a serveis de comunicació de dades de forma ubiqua, mòbil i a velocitats cada vegada més altes. Aquesta demanda de la societat, ha motivat el desenrotllament de la quarta generació de comunicacions mòbils (4G) i la seua evolució cap a la quinta generació (5G). Aquest desenrotllament ha requerit una revolució en la interfície ràdio dels sistemes de comunicacions mòbils i ha modificat en gran manera les seues capacitats i la forma en què es gestionen els seus recursos. Aquest és el cas de la tecnologia coneguda com a Long Term Evolution (LTE) i la seua versió 4G anomenada LTE-Advanced. En concret, aquesta Tesi Doctoral aborda el modelatge, anàlisi de la gestió de recursos ràdio i avaluació de prestacions de l'enllaç descendent de LTE i LTE-Advanced, on, d'entre les característiques de LTE-Advanced, s'ha posat el centre d'atenció en la transmissió multipunt coordinada (CoMP). La Tesi proporciona una descripció detallada de les principals característiques de LTE i LTE-Advanced. La gran complexitat del sistema descrit ha motivat que la metodologia d'estudi s'haja basat en simulació per mitjà d'ordinador. La Tesi realitza una descripció detallada de la metodologia de simulació i del modelatge del sistema empleat, incloent-hi algunes aportacions de l'autor en aquest camp. D'entre aquestes, destaca la provisió de resultats de simulació de nivell d'enllaç que es van usar en el projecte europeu WINNER+ per a l'avaluació de LTE. Pel que fa a l'anàlisi de la gestió de recursos ràdio en LTE, en primer lloc, s'expliquen els fonaments de l'adaptació a l'enllaç i el scheduling. En relació amb el scheduling, es realitza un estudi del concepte de proportional fairness i de la implementació subòptima típicament usada en LTE per a maximitzar aquesta mètrica. L'estudi ha donat com a resultat una modificació de la implementació típica que ha demostrat ser capaç d'augmentar la proportional fairness en l'assignació de recursos amb un baix increment de complexitat. A més, l'anàlisi de l'adaptació a l'enllaç ha desvetllat el problema de l'efecte de "llum de flaix" consistent en la alta variabilitat de la interferència deguda a una ràpida variació de les assignacions de recursos. La Tesi demostra que es poden millorar les prestacions del sistema estabilitzant les decisions del scheduler mitjançant una implementació concreta. En el bloc d'anàlisi de la gestió de recursos d'aquesta Tesi es completa amb l'estudi de CoMP. Específicament, s'estudia una solució amb coordinació de scheduling i conformació de feix (CS/CB), que té en compte suposicions reals i robustes quant al coneixement que els punts coordinats tenen dels canals ràdio dels usuaris servits. La Tesi proposa aquesta solució per la seua senzillesa i capacitat de millorar l'eficiència dels sistemes de comunicacions mòbils, tant en cobertura de velocitats altes de transmissió com en capacitat, encara tenint un coneixement incomplet del canal. Quant a l'avaluació de LTE i LTE-Advanced, aquesta es realitza en dos tipus d'escenaris diferents. D'una banda, els escenaris definits dins del procés d'avaluació de tecnologies IMT-Advanced. Dins d'aquest marc, s'avalua la importància de diferents tècniques de transmissió multi-antena, incloent-hi CoMP, i considerant tràfic de tipus full-buffer. S'ha obtingut una gran millora de prestacions amb la multiplexació espacial d'usuaris i una discreta millora amb CoMP. El segon grup d'escenaris són els definits pel projecte europeu METIS per a l'avaluació de tecnologies 5G, concretament s'han triat un escenari d'interiors amb una oficina, i un d'exteriors amb un estadi esportiu, on s'ha utilitzat un tràfic realista. En aquests escenaris amb desplegaments menys uniformes, o amb un nombre limitat de transmissors provocant la major part de la interferència, és on aquesta Tesi ha trobat la utilitat més gran de / Martín-Sacristán Gandía, D. (2016). 3GPP Long Term Evolution: Performance Analysis and Evolution towards 4G with Coordinated Multi-Point Transmission [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/63261 / TESIS
4

Ordnungsreduktion von elektrostatisch-mechanischen Finite Elemente Modellen für die Mikrosystemtechnik: Ordnungsreduktion von elektrostatisch-mechanischen FiniteElemente Modellen für die Mikrosystemtechnik

Bennini, Fouad 25 January 2005 (has links)
In der vorliegenden Arbeit wird eine Prozedur zur Ordnungsreduktion von Finite Elemente Modellen mikromechanischer Struktur mit elektrostatischem Wirkprinzip entwickelt und analysiert. Hintergrund der Ordnungsreduktion ist eine Koordinatentransformation von lokalen Finite Elemente Koordinaten in globale Koordinaten. Die globalen Koordinaten des reduzierten Modells werden durch einige wenige Formfunktionen beschrieben. Damit wird das Makromodell nicht mehr durch lokale Knotenverschiebungen beschrieben, sondern durch globale Formfunktionen, welche die gesamte Deformation der Struktur beeinflussen. Es wird gezeigt, dass Eigenvektoren der linearisierten mechanischen Struktur einfache und effiziente Formfunktionen darstellen. Weiterhin kann diese Methode für bestimmte Nichtlinearitäten und für verschiedene in Mikrosystemen auftretende Lasten angewendet werden. Das Ergebnis sind Makromodelle, die über Klemmen in Systemsimulatoren eingebunden werden können, die Genauigkeiten einer Finite Elemente Analyse erreichen und für Systemsimulationen typische Laufzeitverhalten besitzen.
5

Device-device communication and multihop transmission for future cellular networks

Amate, Ahmed Mohammed January 2015 (has links)
The next generation wireless networks i.e. 5G aim to provide multi-Gbps data traffic, in order to satisfy the increasing demand for high-definition video, among other high data rate services, as well as the exponential growth in mobile subscribers. To achieve this dramatic increase in data rates, current research is focused on improving the capacity of current 4G network standards, based on Long Term Evolution (LTE), before radical changes are exploited which could include acquiring additional/new spectrum. The LTE network has a reuse factor of one; hence neighbouring cells/sectors use the same spectrum, therefore making the cell edge users vulnerable to inter-cell interference. In addition, wireless transmission is commonly hindered by fading and pathloss. In this direction, this thesis focuses on improving the performance of cell edge users in LTE and LTE-Advanced (LTE-A) networks by initially implementing a new Coordinated Multi-Point (CoMP) algorithm to mitigate cell edge user interference. Subsequently Device-to-Device (D2D) communication is investigated as the enabling technology for maximising Resource Block (RB) utilisation in current 4G and emerging 5G networks. It is demonstrated that the application, as an extension to the above, of novel power control algorithms, to reduce the required D2D TX power, and multihop transmission for relaying D2D traffic, can further enhance network performance. To be able to develop the aforementioned technologies and evaluate the performance of new algorithms in emerging network scenarios, a beyond-the-state-of-the-art LTE system-level simulator (SLS) was implemented. The new simulator includes Multiple-Input Multiple-Output (MIMO) antenna functionalities, comprehensive channel models (such as Wireless World initiative New Radio II i.e. WINNER II) and adaptive modulation and coding schemes to accurately emulate the LTE and LTE-A network standards. Additionally, a novel interference modelling scheme using the 'wrap around' technique was proposed and implemented that maintained the topology of flat surfaced maps, allowing for use with cell planning tools while obtaining accurate and timely results in the SLS compared to the few existing platforms. For the proposed CoMP algorithm, the adaptive beamforming technique was employed to reduce interference on the cell edge UEs by applying Coordinated Scheduling (CoSH) between cooperating cells. Simulation results show up to 2-fold improvement in terms of throughput, and also shows SINR gain for the cell edge UEs in the cooperating cells. Furthermore, D2D communication underlaying the LTE network (and future generation of wireless networks) was investigated. The technology exploits the proximity of users in a network to achieve higher data rates with maximum RB utilisation (as the technology reuses the cellular RB simultaneously), while taking some load off the Evolved Node B (eNB) i.e. by direct communication between User Equipment (UE). Simulation results show that the proximity and transmission power of D2D transmission yields high performance gains for a D2D receiver, which was demonstrated to be better than that of cellular UEs with better channel conditions or in close proximity to the eNB in the network. The impact of interference from the simultaneous transmission however impedes the achievable data rates of cellular UEs in the network, especially at the cell edge. Thus, a power control algorithm was proposed to mitigate the impact of interference in the hybrid network (network consisting of both cellular and D2D UEs). It was implemented by setting a minimum SINR threshold so that the cellular UEs achieve a minimum performance, and equally a maximum SINR threshold to establish fairness for the D2D transmission as well. Simulation results show an increase in the cell edge throughput and notable improvement in the overall SINR distribution of UEs in the hybrid network. Additionally, multihop transmission for D2D UEs was investigated in the hybrid network: traditionally, the scheme is implemented to relay cellular traffic in a homogenous network. Contrary to most current studies where D2D UEs are employed to relay cellular traffic, the use of idle nodes to relay D2D traffic was implemented uniquely in this thesis. Simulation results show improvement in D2D receiver throughput with multihop transmission, which was significantly better than that of the same UEs performance with equivalent distance between the D2D pair when using single hop transmission.
6

High speed moving networks in future wireless systems

Laiyemo, A. O. (Ayotunde Oluwaseun) 05 August 2018 (has links)
Abstract This thesis concentrates on evaluating and improving the throughput performances of mobile users in high speed vehicles. In particular, high speed train (HST) scenarios are considered. Emphasis is placed on practical designs and methods that take into account distinctive HST characteristics. A two-hop communication link, i.e., base station (BS)-to-HST and HST-to-onboard users (OBUs) is adopted. The main target is to improve the throughput performance on the BS-to-HST communication link, which is assumed to be the main bottleneck in the whole communication link, since the HST-to-OBU communication link is assumed to have good channel quality due to the short link distance with relatively stationary OBUs. The algorithms developed are assessed through link and system level simulations. A theoretical and practical study of the throughput maximization problem in a single and multi-cell multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) train scenario are considered with and without cooperation between train carriages. Two low-complexity transmission schemes based on simple antenna selection (AS) methods with spatial multiplexing (SM) are proposed. The simulation results demonstrate that large antenna arrays with AS and SM transmission strategies have the potential to significantly improve the throughput of the BS-to-train link in HST scenarios. Resource sharing methodologies between the moving relay nodes (MRNs) on the HST and ground macro users (GMUs) were also studied in a multi-cell MIMO-OFDM train scenario. Direct application of existing resource scheduling methods will not be appropriate to efficiently and fairly share resources, since the MRNs and the GMUs have different processing capabilities. Hence, two hybrid resource scheduling methods are analyzed in conjunction with joint and disjoint resource management. The tradeoff between the number of MRNs and receive antennas that should be installed on an HST was also examined in the context of throughput performance and capital expenditure. Results show that joint scheduling does not provide the best overall performance and there is a need to schedule each group of mobile terminals (MTs) separately. Finally, the feasibility of the use of higher frequency bands (HFBs) was examined in HST scenarios. A timer-based beam selection scheme for HST, which does not require any training time to select the appropriate beam is also proposed. The proposed beam selection scheme (PBSS) displays a close performance to the ideal singular value decomposition (SVD) scheme. / Tiivistelmä Tämä väitöskirja keskittyy mobiilikäyttäjien tiedonsiirtonopeuksien arviointiin ja parantamiseen nopeasti liikkuvissa kulkuneuvoissa. Työ käsittelee erityisesti tiedonsiirtoa suurnopeusjunissa. Työssä korostetaan käytännön menetelmiä, jotka ottavat huomioon nopeasti liikkuvien junien tiedonsiirron erityispiirteet. Työssä käytetään kahden hypyn linkkimallia, jossa tiedonsiirto kulkee tukiasemalta junaan ja junasta käyttäjälle, joka on junassa. Päätavoite on parantaa datanopeuksia tukiaseman ja junan välisessä tiedonsiirtolinkissä, jonka uskotaan olevan suurin pullonkaula koko tiedonsiirtolinkissä, koska junan ja lähes paikallaan olevan käyttäjän välinen kanava voidaan olettaa hyvälaatuiseksi linkin lyhyyden vuoksi. Kehitettyjen algoritmien suorituskykyä arvioidaan linkki- ja järjestelmätason simulaatioilla. Työssä tutkitaan tiedonsiirtonopeuden maksimointiongelmaa teoreettisella ja käytännön tasolla yhden ja usean solun MIMO OFDM junaskenaarioissa, joissa junan vaunut tekevät tai eivät tee yhteistyötä. Työssä esitetään kaksi alhaisen kompleksisuuden lähetysmenetelmää, jotka hyödyntävät yksinkertaista antennin valintamenetelmää ja tilatason multipleksointia. Simulointitulokset osoittavat, että suuret antenniryhmät, jotka hyödyntävät näitä lähetysmenetelmiä, voivat parantaa merkittävästi tiedonsiirtonopeutta tukiasemalta junaan päin. Työssä tutkitaan myös resurssien jakomenetelmiä liikkuvien junassa olevien releiden ja maatason makrokäyttäjien välillä monen solun MIMO-OFDM junaskenaariossa. Nykyisten resurssinhallintamenetelmien käyttö ei ole suoraan mahdollista tehokasta ja oikeudenmukaista resurssien jakoa, koska releillä ja makrokäyttäjillä on erilaiset prosessointikyvyt. Tämän vuoksi työssä analysoidaan kahta hybridimenetelmään resurssien skeduloinnille. Tutkimukset selventävät tasapainoa releiden lukumäärän ja junaan asennettavien vastaanotinantennien välillä tiedonsiirtonopeuden ja kustannusten osalta. Tulokset osoittavat, että yhteinen resurssien jako ei saavuta parasta suorituskykyä, eikä ole tarvetta ajoittaa jokaista matkaviestinterminaaliryhmää erikseen. Lopuksi työssä tutkitaan korkeampien taajuusalueiden soveltuvuutta tiedonsiirtoon suurnopeusjunissa. Työssä ehdotetaan ajastinpohjaista keilanvalintamenetelmää, joka ei vaadi opetusjaksoa sopivan keilan valintaan. Ehdotetun menetelmän saavuttama suorituskyky on lähellä ideaalisen singulaariarvohajotelmaa hyödyntävän menetelmän suorituskykyä.
7

Analysis of 5G Mobile Broadband Solutions in Rural and Remote Areas : A Case Study of Banten, Indonesia

Sarah, Annisa January 2017 (has links)
Providing a broadband access anytime and anywhere is one of the visions of the future 5G network. However, deploying a reliable network connection in remote/rural areas has been a challenging task because of its wide area that needed to be covered and a low density of user compared to urban area. Different geography and traffic condition may need different system solution. In this thesis, we analyze several solutions to providing a broadband access network in practical remote and rural area in Banten, Indonesia: Leuwidamar (remote) and Panimbang (rural). Two approaches are discussed, first one is fulfilling futuristic traffic demand by having LTE System, and the second one is by having 5G System. We included three key technology components in a 5G network: occupying wide bandwidth in high frequency, applying UE-Specific Beamforming, and implementing Carrier Aggregation (CA) scheme. We also account a rain attenuation when deploying a network in high operating frequency, since Indonesia has a high rain rate thus it is important to be considered. We compared five cases of solution: Case 1 is Single Carrier (SC) LTE 1.8 GHz system; Case 2 is Carrier Aggregation (CA) LTE 1.8 GHz + 2.6 GHz; Case 3 is SC 5G 15GHz; Case 4 is SC 5G 28 GHz; Case 5 is CA LTE 1.8 GHz + 5G 15 GHz. Basedon the evaluation, in Leuwidamar scenario, Case 5 gives us the least number of BS needed in order to meet the futuristic requirement with only 1.6 x densification from the current network. In Panimbang, the least number of BS neededis offered by two cases, Case 3 and Case 5 without any additional BS needed(1x densification). However, the solution with the lowest energy consumption for both area is Case 3. This is due to the fact that the carrier aggregation scenario needs additional power to generate the second system. Furthermore, if we introduce cell DTX ability in the 5G network, the Case 3 can give us impressive amount of energy saving, with 97% saving for Leuwidamar and 94% saving for Panimbang, compared to Case 1 solution without any DTX Capability. / Att tillhandahålla bredbandsanslutning när som helst och var som helst är en av visionerna för det framtida 5G-nätverket. Att använda en tillförlitlig nätverksanslutning i avlägsna- eller landsbygdsområden har dock varit en utmanande uppgift på grund av det breda området som måste täckas och den låga täthetenav användare jämfört med stadsområden. Olika geografiska förhållanden och trafikförhållanden kan behöva olika systemlösningar. I denna avhandling analyserarvi flera lösningar för att tillhandahåller ett bredbandsnätverk i verkligt avlägset eller landsbygdsområde i Banten, Indonesien: Leuwidamar (avlägset) och Panimbang (landsbygd). Två strategier diskuteras, den första uppfyller framtida trafikbehov genom att ha LTE-system och den andra är genom att ha5G System. Vi inkluderade tre viktiga teknikkomponenter i 5G-nätverk: bredbandbredd och hög frekvens, tillämpar UE-specifik strålformning och implementeringav carrier aggregation (CA). Vi redovisar också en dämpning av regn när nätverket används i hög bärvågsfrekvens, eftersom Indonesien har en hög regnhastighet och det är viktigt att överväga. Vi jämförde fem fall av lösning:Fall 1 är Single Carrier (SC) eller Enkelbärare LTE 1.8 GHz system; Fall 2 är bärareaggregation (CA) LTE 1,8 GHz + 2.6 GHz; Fall 3 är SC 5G 15 GHz;Fall 4 är SC 5G 28 GHz; Fall 5 är CA LTE 1.8 GHz + 5G 15 GHz. Baserat på utvärderingen, i Leuwidamar-scenariot,ger Fall 5 oss det minsta antalet BSsom behövs för att möta det futuristiska kravet med endast 1.6 gångers förtätning från nuvarande nätverk. I Panimbang erbjuds det minsta antalet BS somkrävs i två fall, fall 3 och fall 5 utan ytterligare BS behövs (1 gångers förtätning). Lösningen med den lägsta energiförbrukningen för båda områdena är fall 3. Detta beror på att bäraraggregations scenariot behöver ytterligare effekt för att generera det andra systemet. Om vi introducerar cell DTX-funktionen i 5G-nätverket kan Fall 3 ge oss en imponerande energibesparing, med 97% minskning för Leuwidamar och 94% för Panimbang jämfört med Fall 1-lösning utan DTX-funktion.

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