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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

Resource Allocation for Smart Phones in 4G LTE-Advanced Carrier Aggregation

Kurrle, Rebecca Lynne 10 December 2012 (has links)
The purpose of this thesis is to explore the concept of resource scheduling and pricing and its relation to carrier aggregation. The first main topic is a modified Frank Kelly algorithm that allows for the use of utility functions that are piecewise concave, but not a member of a strictly \'diminishing return\' model. This adjustment to the Frank Kelly algorithm allows resource allocation to take into account devices with multiple applications. The second topic introduces the idea of scheduling resources in a carrier aggregation scenario assuming the carriers are scheduled sequentially. / Master of Science
2

Traffic Scheduling for LTE Advanced

Tang, Zhiqiang January 2010 (has links)
Long Term Evolution (LTE) is becoming the first choice of operators when constructingthe new network infrastructure, because of its high throughput and lowlatency. Although the LTE can offer high speed data service as a benefit of widebandapplication, the large bandwidth also results in huge control signaling cost.This thesis studies how the available radio resources should be allocated todifferent users for the particular purpose. Three proposals are presented in thisthesis. The first two aim at maximizing the overall net capacity. The factors ofchannel conditions and control signaling cost are considered in the first proposalwhereas power control is supplemented as an additional factor in the second one.The third proposal aims at achieving a tradeoff between subframe efficiency andaverage data rate. Channel conditions and control signaling cost are taken intoconsideration.Resource blocks scheduling under a control signaling cost constraint is feasiblewith the knowledge of the channel condition of users. This is obtained from channelstate information directly. The first proposal studies how this scheduling isdone. The second proposal takes power allocation scheme into account. In termsof computational complexity, the methods of internal water-filling and externalwater-filling are described in the second proposal. The simulation results illustratethat the net capacity in the first proposal can be enhanced by about 5% -60% in the second proposal. The exact percentage of increase depends on differentcontrol signaling penalty.The third proposal discusses how to implement flexible subframe length underthe Rayleigh fading channel condition in the LTE system. The objective is toachieve subframe efficiency as high as possible, while maintaining the maximumaverage data rate. The simulation results illustrate that the optimal subframelength depends on control signaling cost penalty as well as on Doppler frequency.Finally, the fairness of the first proposal is compared with the improved versionsof Round Robin, Dynamic Allocation and Proportional Fair scheduling algorithms.The simulation results show that Round Robin and Dynamic Allocationoutperform the first proposal under a certain condition. / LOLA (Achieving Low Latency in Wireless Communication) is funded by EU FP7 (European Community’s Seventh Framework Programme).
3

[en] COVERAGE AND CAPACITY PLANNING FOR LTE-ADVANCED NETWORKS / [pt] PLANEJAMENTO DE COBERTURA E CAPACIDADE DE REDES LTE-ADVANCED

DANIEL YUJI MITSUTAKE CUETO 09 November 2018 (has links)
[pt] O acesso sem fio de banda larga está se tornando uma realidade, não apenas para uso corporativo e doméstico, mas para usuários com mobilidade. Dos estimados 1.8 bilhão de pessoas que já utilizam banda larga desde 2012, cerca de dois terços serão consumidores de banda larga móvel e a maioria será servida por redes HSPA (High Speed Packet Access) e LTE-A (Long Term Evolution-Advanced), uma evolução para as redes 4G,capaz de oferecer velocidades acima de 500 Mbps. O planejamento celular tem como objetivo estabelecer a rede de rádio adequada e eficiente em termos de cobertura, capacidade, qualidade de serviço (QoS), custo, utilização de frequências, a implantação de equipamentos e desempenho. O objetivo deste trabalho é estudar dos métodos de planejamento de cobertura e capacidade de sistemas celulares LTE-Advanced e propor uma metodologia passo-a-passo para o planejamento inicial e dimensionamento do número de estações rádio base necessárias para atender uma determinada área de serviço com a capacidade requerida. Um estudo de caso é apresentado, ilustrando a aplicação da metodologia proposta. É apresentada também uma análise comparativa dos recursos requeridos para atender às especificações do projeto quando são utilizadas as bandas de frequência de 2.6 GHz, atualmente autorizada no Brasil, e a banda de 700 MHz, que está em consideração para uso futuro. Os resultados quantificam claramente as vantagens do uso da banda de 700 MHz em relação à banda de 2.6 GHz. / [en] The wireless broadband is becoming a reality, not only for corporate and domestic use, but for mobile users. Of the estimated 1.8 billion people already using broadband since 2012, about two thirds will be mobile broadband consumers and the majority will be served by HSPA (High Speed Packet Access) and LTE-A (Long Term Evolution-Advanced), an evolution to 4G networks, able to offer speeds up to 500 Mbps. The cell planning establishes a radio network properly and efficiently in terms of coverage, capacity, quality of service (QoS), cost, frequency usage, deployment of equipment and performance. The objective of this work is to study the methods of planning coverage and capacity of LTE-A cellular systems and propose a methodology step-by-step for the initial planning and dimensioning of the number of base stations required to meet a given service area with the required capacity. A study case is presented, illustrating the application of the proposed methodology. It also presented a comparative analysis of the required resources to meet the project specifications when used frequency bands of 2.6 GHz, nowadays licensed in Brazil, and the 700 MHz band, which is under consideration for future use. The results clearly quantify the advantages of the use of the 700 MHz band relative to the 2.6 GHz band.
4

Frame Allocation and Scheduling for Relay Networks in the LTE Advanced Standard

Roth, Stefan January 2010 (has links)
<p>The use of relays is seen as a promising way to extend cell coverage and increase rates in LTE Advanced networks. Instead of increasing the number of base stations (BS), relays with lower cost could provide similar gains. A relay will have a wireless link to the closest BS as only connection to the core network and will cover areas close to the cell edge or other areas with limited rates.</p><p>Performing transmissions in several hops (BS-relay & relay-user) requires more radio resources than using direct transmission. This thesis studies how the available radio resources should be allocated between relays and users in order to maximize throughput and/or fairness. Time and frequency multiplexed backhaul is investigated under a full buffer traffic assumption. It is shown that the system will be backhaul limited and that the two ways of multiplexing will perform equally when maximising throughput and/or fairness. The analysis results in a set of throughput/fairness suboptimal solutions, dependant on how many relays are used per cell. The results are verified by simulations, which also show the limiting effects on throughput caused by interference between relays.</p><p>It is also analysed how the resource allocation should be done given non-fullbuffer traffic. A resource allocation that minimises packet delay given a certain number of relays per cell is presented. The analysis is based on queuing theory.</p><p>Finally some different schedulers and their suitability for relay networks are discussed. Simulation results are shown, comparing the throughput and fairness of Round Robin, Weighted Round Robin, Proportional Fairness and Weighted Proportional Fairness schemes. It is shown that allocating the resource among the relays according to the number of users served by the relays improves the fairness.</p>
5

Frame Allocation and Scheduling for Relay Networks in the LTE Advanced Standard

Roth, Stefan January 2010 (has links)
The use of relays is seen as a promising way to extend cell coverage and increase rates in LTE Advanced networks. Instead of increasing the number of base stations (BS), relays with lower cost could provide similar gains. A relay will have a wireless link to the closest BS as only connection to the core network and will cover areas close to the cell edge or other areas with limited rates. Performing transmissions in several hops (BS-relay &amp; relay-user) requires more radio resources than using direct transmission. This thesis studies how the available radio resources should be allocated between relays and users in order to maximize throughput and/or fairness. Time and frequency multiplexed backhaul is investigated under a full buffer traffic assumption. It is shown that the system will be backhaul limited and that the two ways of multiplexing will perform equally when maximising throughput and/or fairness. The analysis results in a set of throughput/fairness suboptimal solutions, dependant on how many relays are used per cell. The results are verified by simulations, which also show the limiting effects on throughput caused by interference between relays. It is also analysed how the resource allocation should be done given non-fullbuffer traffic. A resource allocation that minimises packet delay given a certain number of relays per cell is presented. The analysis is based on queuing theory. Finally some different schedulers and their suitability for relay networks are discussed. Simulation results are shown, comparing the throughput and fairness of Round Robin, Weighted Round Robin, Proportional Fairness and Weighted Proportional Fairness schemes. It is shown that allocating the resource among the relays according to the number of users served by the relays improves the fairness.
6

LTE/LTE-Advanced for Vehicular Safety Applications

Soleimani, Hossein 11 July 2018 (has links)
IEEE 802.11p, the known standard for Vehicular Adhoc NETworks (VANETs), suffers from scalability issues and unbounded delay. In addition, the desire to use networks already in existence has created motivation for using cellular networks for vehicular applications. LTE-Advanced is one of the most promising access technologies in the wireless field, providing high data rate, low latency, and a large coverage area. Thus, LTE/LTE-A can be potential access technologies for supporting vehicular applications. Vehicular safety applications are based on broadcasting messages to neighboring vehicles. The vehicle location precision is crucial for safety applications. Thus, the freshness of the information (i.e. vehicle location) at the neighboring vehicles is very important. As LTE is an infrastructure-based network, all transmissions should pass through it. When the load of the network is high compared to the available resources, large delays may occur. The focus of this thesis is to propose solutions to make LTE suitable for vehicular safety applications. The first solution is to adapt the vehicular safety application to be suitable in LTE network. For this purpose, we propose an adaptation of the safety message generation rate. This adaptation uses a queueing model to compute the freshness of the information of vehicles at the destination, based on their message generation rates. It then adjusts the generation periods to provide a similar accuracy for all vehicles. The second approach is to modify the LTE and make it suitable for these kinds of applications. Thus, we proposed a scheduler for LTE which is suitable for vehicular safety applications. It considers the speed and location of the vehicles to allocate the resources to them for the transmission of safety messages. We also studied the message dissemination in the downlink, and proposed an efficient way to deliver the safety messages to the neighboring vehicles. Finally, we propose a scheme that uses both LTE-D2D and LTE-cellular communication for the transmission of safety messages. The centralized location information is used for Device-to-Device (D2D) pair discovery and resource allocation. The proposed scheme provides resource efficiency by enabling the reuse of the resources by vehicles. We also study the effect of the awareness range and period of updating location information at the server on resource usage and accuracy of D2D pair detection.
7

Designing of LTE-Advanced Downlink Transceiver on a Physical Layer

Shahid, Samiallah, Mohammad, Saqib January 2013 (has links)
The evolved version of LTE is LTE-Advanced which is being developed by 3GPP. LTE-Advanced will meet or go beyond the requirements of the International Telecommunication Union (ITU) for the fourth generation (4G) radio communication standard known as IMT-Advanced. LTEAdvanced is primarily considered as a part of Release 10 of 3GPP specifications. The LTE-Advanced specifications will continue to be developed in subsequent 3GPP releases. The complete physical layer structure has been employed by using the latest 3GPP standards. Furthermore, technologies such as Orthogonal Frequency Division Multiplexing (OFDM) and Multiple Input Multiple Output (MIMO) have also been implemented and integrated with LTEAdvanced. The Multiple Access Scheme in Advanced Mobile radio system has to meet the specific requirements such as: high throughput, robustness, efficient Bit Error Rate (BER), high spectral efficiency, minimum delays, low computational complexity, low Peak to Average Power Ratio (PAPR), low error probability etc. In order to investigate the LTE-Advanced transceiver a thorough study has been carried out using MATLAB Simulink using AWGN and Rayleigh fading channel. This report investigates the performance of OFDMA and various MIMO configurations of LTEAdvanced physical layer, along with diverse modulation techniques such 16QAM and QPSK,the results are then demonstrated on BER and signal to noise ratio graphs. AWGN and Rayleigh fading models are also used to determine the performance of LTE-Advanced in presence of noise and fading.
8

A 70-W Asymmetrical Doherty Power Amplifier for 5G Base Stations

Abdulkhaleq, Ahmed M., Al-Yasir, Yasir I.A., Ojaroudi Parchin, Naser, Brunning, J., McEwan, N., Rayit, A., Abd-Alhameed, Raed, Noras, James M., AbdulJabbar, N. 22 August 2018 (has links)
Yes / Much attention has been paid to making 5G developments more en-ergy efficient, especially in view of the need for using high data rates with more complex modulation schemes within a limited bandwidth. The concept of the Doherty power amplifier for improving amplifier efficiency is explained in addi-tion to a case study of a 70W asymmetrical Doherty power Amplifier using two GaN HEMTs transistors with peak power ratings of 45W and 25W. The rationale for this choice of power ratio is discussed. The designed circuit works in the 3.4GHz frequency band with 200 MHz bandwidth. Rogers RO4350B substrate with dielectric constant εr=4.66 and thickness 0.035 mm is used. The perfor-mance analysis of the Doherty power amplifier is simulated using AWR MWO software. The simulated results showed that 54-64% drain efficiency has been achieved at 8 dB back-off within the specified bandwidth with an average gain of 10.7 dB.
9

Evaluation of Call Mobility on Network Productivity in Long Term Evolution Advanced (LTE-A) Femtocells

Sawant, Uttara 12 1900 (has links)
The demand for higher data rates for indoor and cell-edge users led to evolution of small cells. LTE femtocells, one of the small cell categories, are low-power low-cost mobile base stations, which are deployed within the coverage area of the traditional macro base station. The cross-tier and co-tier interferences occur only when the macrocell and femtocell share the same frequency channels. Open access (OSG), closed access (CSG), and hybrid access are the three existing access-control methods that decide users' connectivity to the femtocell access point (FAP). We define a network performance function, network productivity, to measure the traffic that is carried successfully. In this dissertation, we evaluate call mobility in LTE integrated network and determine optimized network productivity with variable call arrival rate in given LTE deployment with femtocell access modes (OSG, CSG, HYBRID) for a given call blocking vector. The solution to the optimization is maximum network productivity and call arrival rates for all cells. In the second scenario, we evaluate call mobility in LTE integrated network with increasing femtocells and maximize network productivity with variable femtocells distribution per macrocell with constant call arrival rate in uniform LTE deployment with femtocell access modes (OSG, CSG, HYBRID) for a given call blocking vector. The solution to the optimization is maximum network productivity and call arrival rates for all cells for network deployment where peak productivity is identified. We analyze the effects of call mobility on network productivity by simulating low, high, and no mobility scenarios and study the impact based on offered load, handover traffic and blocking probabilities. Finally, we evaluate and optimize performance of fractional frequency reuse (FFR) mechanism and study the impact of proposed metric weighted user satisfaction with sectorized FFR configuration.
10

Capacity Enhancement Approaches for Long Term Evolution networks: Capacity Enhancement-Inspired Self-Organized Networking to Enhance Capacity and Fairness of Traffic in Long Term Evolution Networks by Utilising Dynamic Mobile Base-Stations

Alrowili, Mohammed F.H. January 2018 (has links)
The long-term evolution (LTE) network has been proposed to provide better network capacity than the earlier 3G network. Driven by the market, the conventional LTE (3G) network standard could not achieve the expectations of the international mobile telecommunications advanced (IMT-Advanced) standard. To satisfy this gap, the LTE-Advanced was introduced with additional network functionalities to meet up with the IMT-Advanced Standard. In addition, due to the need to minimize operational expenditure (OPEX) and reduce human interventions, the wireless cellular networks are required to be self-aware, self-reconfigurable, self-adaptive and smart. An example of such network involves transceiver base stations (BTSs) within a self-organizing network (SON). Besides these great breakthroughs, the conventional LTE and LTE-Advanced networks have not been designed with the intelligence of scalable capacity output especially in sudden demographic changes, namely during events of football, malls, worship centres or during religious and cultural festivals. Since most of these events cannot be predicted, modern cellular networks must be scalable in terms of capacity and coverage in such unpredictable demographic surge. Thus, the use of dynamic BTSs is proposed to be used in modern and future cellular networks for crowd and demographic change managements. Dynamic BTSs are complements of the capability of SONs to search, determine and deploy less crowded/idle BTSs to densely crowded cells for scalable capacity management. The mobile BTSs will discover areas of dark coverages and fill-up the gap in terms of providing cellular services. The proposed network relieves the LTE network from overloading thus reducing packet loss, delay and improves fair load sharing. In order to trail the best (least) path, a bio-inspired optimization algorithm based on swarm-particle optimization is proposed over the dynamic BTS network. It uses the ant-colony optimization algorithm (ACOA) to find the least path. A comparison between an optimized path and the un-optimized path showed huge gain in terms of delay, fair load sharing and the percentage of packet loss.

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