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Cooperative uplink Inter-Cell Interference (ICI) mitigation in 5G networksPitakanda, Pitakandage Tinith Asanga January 2017 (has links)
In order to support the new paradigm shift in fifth generation (5G) mobile communication, radically different network architectures, associated technologies and network operation algorithms, need to be developed compared to existing fourth generation (4G) cellular solutions. The evolution toward 5G mobile networks will be characterized by an increasing number of wireless devices, increasing device and service complexity, and the requirement to access mobile services ubiquitously. To realise the dramatic increase in data rates in particular, research is focused on improving the capacity of current, Long Term Evolution (LTE)-based, 4G network standards, before radical changes are exploited which could include acquiring additional 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 heavy inter cell interference in addition to the other factors such as fading and path-loss. In this direction, this thesis focuses on improving the performance of cell-edge users in LTE and LTE-Advanced networks by initially implementing a new Coordinated Multi-Point (CoMP) technique to support future 5G networks using smart antennas to mitigate cell-edge user interference in uplink. Successively a novel cooperative uplink inter-cell interference mitigation algorithm based on joint reception at the base station using receiver adaptive beamforming is investigated. Subsequently interference mitigation in a heterogeneous environment for inter Device-to-Device (D2D) communication underlaying cellular network is investigated as the enabling technology for maximising resource block (RB) utilisation in emerging 5G networks. The proximity of users in a network, achieving higher data rates with maximum RB utilisation (as the technology reuses the cellular RB simultaneously), while taking some load off the evolved Node B (eNodeB) i.e. by direct communication between User Equipment (UE), has been explored. Simulation results show that the proximity and transmission power of D2D transmission yields high performance gains for D2D receivers, which was demonstrated to be better than that of cellular UEs with better channel conditions or in close proximity to the eNodeB in the network. It is finally demonstrated that the application, as an extension to the above, of a novel receiver beamforming technique to reduce interference from D2D users, 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.
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Controle de potÃncia e estratÃgias de eficiÃncia energÃtica para comunicaÃÃes D2D subjacentes redes celulares / Power control and energy efficiency strategies for D2D communications underlying cellular networksYuri Victor Lima de Melo 14 July 2015 (has links)
Ericsson Brasil / Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Em um mundo onde as pessoas contam com
smartphone, smartwatch, tablet e outros
dispositivos para mantÃ-las conectadas onde quer que vÃo, t
odos esperam que seus
aplicativos sejam executados sem problemas, tais como cham
adas abandonadas,
download
lento e vÃdeos com saltos.
Neste contexto, comunicaÃÃo dispositivo-a-dispositivo (
do inglÃs, Device-to-Device (D2D))
constitui uma tecnologia promissora, pois à um tipo de comun
icaÃÃo direta e utiliza baixa
potÃncia entre dispositivos prÃximos, permitindo-se desv
iar o trÃfego da rede mÃvel, aumentar
a eficiÃncia espectral e de potÃncia. Do ponto de vista do assi
nante, D2D significa usar
aplicaÃÃo sem problemas e aumentar o tempo de vida da bateria
do celular.
No entanto, a fim de realizar os ganhos potenciais das comunic
aÃÃes D2D, algumas
questÃes-chave devem ser abordadas, pois as comunicaÃÃes D
2D podem aumentar a
interferÃncia co-canal e comprometer a qualidade do enlace
das comunicaÃÃes celulares.
Esta dissertaÃÃo foca em tÃcnicas de Gerenciamento de Recur
sos de RÃdio (do inglÃs, Radio
Resource Management (RRM)) para mitigar a interferÃncia co
-canal para comunicaÃÃes D2D
que se baseiam na EvoluÃÃo de Longo Prazo (do inglÃs, Long Ter
m Evolution (LTE)), visando
a reduÃÃo da interferÃncia intra- e inter-celular e na melho
ria da eficiÃncia energÃtica. Os
principais esquemas de Controle de PotÃncia (do inglÃs, Pow
er Control (PC)) (e.g. OLPC,CLPC
e SDPC) e um esquema hÃbrido (CLSD) sÃo calibrados e utilizad
os no cenÃrio macro ou micro
multicelular, usando diferentes cargas e InformaÃÃo do Est
ado do Canal (do inglÃs, Channel
State Information (CSI)) perfeita ou imperfeita. AlÃm diss
o, o impacto da inclinaÃÃo da antena
(
downtilt
) à analisado, que à usada para ajustar o raio de cobertura de u
ma Evolved Node
B (eNB) e reduzir a interferÃncia co-canal, aumentando o iso
lamento de cÃlulas.
Os resultados numÃricos indicam que os regimes de controle d
e potÃncia e inclinaÃÃo
da antena, devidamente calibrados, podem fornecer ganhos p
ara a comunicaÃÃo celular e
D2D. Em outras palavras, a tecnologia D2D pode ser utilizada
para aumentar ainda mais
a eficiÃncia de espectro e a eficiÃncia energÃtica se algoritm
os de RRM forem utilizados
adequadamente / In a world where people count on their smartphone, smartwatch, tablet and other devices to keep them connected wherever they go, they expect its application to run without problems, such as dropped calls, slow download and choppy videos.
In this context, Device-to-Device (D2D) communication represents a promising technology, because it is a direct and low-power communication between devices close, allowing to offload the data transport network, increase spectral and power efficiency. From the subscriber point of view, D2D means to use applications without problem and increase battery life. However, in order to realize the potential gains of D2D communications, some key issues must be tackled, because D2D communications may increase the co-channel interference and compromise the link quality of cellular communications.
This masterâs thesis focuses on Radio Resource Management (RRM) techniques, especially Power Control (PC) schemes, to mitigate the co-channel interference for D2D communications
underlaying a Long Term Evolution (LTE) network, aiming at the reduction of the intra- and inter- cell interference and at the improvement of energy efficiency. The main PC schemes (e.g. OLPC, CLPC and SDPC) and a hybrid scheme (CLSD) are calibrated and used in macro- or micro- multicell scenario, using different loads and imperfect Channel State Information (CSI).
In addition, the impact of downtilt is analyzed, which is used to adjust the coverage radius of an Evolved Node B (eNB) and reduce co-channel interference by increasing cell isolation.
The numerical results indicate that PC schemes and downtilt, duly calibrated, can provide gains to cellular and D2D communications. In other words, D2D technology can be used to further increase the spectral and energy efficiency if RRM algorithms are used suitably.
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Explorando interações em redes sociais online, comunicação dispositivo-a-dispositivo e estratégias de cache para uso eficiente de recursos em redes celulares / Exploiting on-line social interactions, D2D communication and caching strategies for celular network resource efficiencyMoraes, Fausto da Silva 09 November 2016 (has links)
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Previous issue date: 2016-11-09 / For the future of cellular networks is estimated a significant increase in the number
of connected devices and the bulk data traffic, especially video content. That poses
as a challenge for the next generation network. With the rise of new communications
paradigm, D2D communication emerge as potential approach for cellular network data
offloading, especially when paired with caching solutions within the network. Also, the
impact of viral videos could be mitigated by proactively caching the contents being shared
on Online Social Networks (OSNs). This work presents a new approach to proactive
content cache for D2D-enabled networks, that is aware of users social interaction on
OSN’s. Our proposal consists in the combination of user mobile and social informations
to find the best located device to cache a content being shared online. Results obtained
through simulation show that the proposed approach can improve offload rate, reduce
energy consumption and provide a faster content access when compared with other work
in literature. / As estimativas de um crescimento significativo do número de dispositivos conectados
às redes sem fio e móveis, e do aumento do volume de dados trafegados, em especial
o tráfego de conteúdo em vídeo, representam um desafio para a próxima geração de
redes celulares. Com o surgimento de novos paradigmas de redes sem fio, a comunicação
D2D (Dispositivo-a-Dispositivo) figura como uma abordagem promissora para permitir
o descarregamento de dados da rede celular, principalmente quando aliada a técnicas
de cache de conteúdo nos dispositivos dos usuários. Além disso, as informações de
interações dos usuários em redes sociais online poderiam ser empregadas para suavizar o
impacto dos vídeos virais sendo compartilhados entre os usuários, através de uma solução
de cache proativa. Nesta dissertação, apresentamos uma proposta de cache proativo de
conteúdo ciente às interações sociais online para redes com comunicação D2D. Em nossa
proposta, determinamos de forma probabilística qual o melhor dispositivo para armazenar
um conteúdo que esteja sendo compartilhado entre os usuários com base nas informações
de contatos entre os usuários na rede D2D. Os resultados coletados com o simulador ns-3
mostram que a proposta apresentada pode melhorar o descarregamento de dados da rede
celular, reduzir os gastos de energia dos dispositivos dos usuários, e fornecer tempos de
transmissão de conteúdo menores, em comparação com outro trabalho da literatura,
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Heterogenní propojení mobilních zařízení v bezdrátových systémech 5. generace / Heterogeneous Connectivity of Mobile Devices in 5G Wireless SystemsMašek, Pavel January 2017 (has links)
Předkládaná disertační práce je zaměřena na "heterogenní propojení mobilních zařízení v bezdrátových systémech 5. generace". Navzdory nepochybnému pokroku v rámci navržených komunikačních řešení postrádají mobilní sítě nastupující generace dostatečnou šířku pásma a to hlavně kvůli neefektivnímu využívání rádiového spektra. Tato situace tedy v současné době představuje řadu otázek v oblasti výzkumu. Hlavním cílem této disertační práce je proto návrh nových komunikačních mechanismů pro komunikaci mezi zařízeními v bezprostřední blízkosti s asistencí mobilní sítě a dále pak návrh a implementace algoritmů pro dynamické přidělování frekvenčního spektra v nastupujících mobilních sítích 5G. Navrhnuté komunikační mechanismy a algoritmy jsou následně komplexně vyhodnoceny pomocí nově vyvinutých simulačních nástrojů (kalibrovaných s využitím 3GPP trénovacích dat) a zejména pak v experimentální mobilní síti LTE-A, která se nachází v prostorách Vysokého učení technického v Brně, Česká Republika. Získané praktické výsledky, které jsou podpořeny zcela novou matematickou analýzou ve speciálně navržených charakteristických scénářích, představují řešení pro vlastníka spektra v případě požadavků na jeho dynamické sdílení. Tato metoda tedy představuje možnost pro efektivnější využití spektra v rámci mobilních sítí 5G bez degradace kvality služeb (QoS) a kvality zážitků (QoE) pro koncové uživatele. Vědecký přínos dosažených výsledků dokazuje fakt, že některé z principů představených v této disertační práci byly zahrnuty do celosvětově uznávaného standardu (specifikace) 3GPP Release 12.
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