Utilização da rede SFN para expansão da rede de retransmissão regional da TV digital aberta terrestre

Orientador: Yuzo IanoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e ComputaçãoResumo: Este trabalho apresenta uma proposta para as redes retransmissoras de TV aberta que pode ser implantada com o advento da TV digital no Brasil, baseada em modulações utilizando sistemas COFDM. Diferentemente do sistema tradicional que se baseia na retransmissão em multifreqüência (MFN), a proposta aqui descrita propõe o uso de uma rede em freqüência única (SFN) para a retransmissão. O ponto inicial é a atual rede com múltiplos canais de retransmissão analógicos existente. Sua cobertura deverá ser replicada pela nova rede em um único canal onde trafega uma determinada programação de uma emissora de TV. A modificação proposta apresenta vantagens para as emissoras de televisão que possuam redes de retransmissão destinadas a ampliar sua cobertura em uma área regional com várias cidades, obtendo um ambiente de rede muito mais controlado e seguro. O trabalho apresenta simulações de cobertura mostrando que a possibilidade de trabalhar com redes SFN surge como uma alternativa mais rápida de viabilização da TV Digital para o interior do BrasilAbstract: This work presents an approach to the network relay station for free broadcasting television that may constructed with the future digital television in Brazil based on COFDM modulation. Differently of the traditional system, the network relay in multi frequencies (MFN), the proposal here described considers the use of a net in only one frequency (SFN) for the network relay. The initial point is the current network with multiple analogical channels of existing network relay. Its covering will have to be talked back by the new net in an unique channel where only one TV programming passes through. The modification proposal presents advantages for the network relay broadcasting television destined to extend its covering in a local area with some cities being gotten environment of a much more controlled and safe net. The work presents covering simulation showing that the possibility to work with nets SFN appears as a faster alternative of accomplishment of the Digital TV for the regional area of BrazilMestradoTelecomunicações e TelemáticaMestre em Engenharia Elétric

Potentzia domeinuko NOMA 5G sareetarako eta haratago

Tesis inglés 268 p. -- Tesis euskera 274 p.During the last decade, the amount of data carried over wireless networks has grown exponentially. Several reasons have led to this situation, but the most influential ones are the massive deployment of devices connected to the network and the constant evolution in the services offered. In this context, 5G targets the correct implementation of every application integrated into the use cases. Nevertheless, the biggest challenge to make ITU-R defined cases (eMBB, URLLC and mMTC) a reality is the improvement in spectral efficiency. Therefore, in this thesis, a combination of two mechanisms is proposed to improve spectral efficiency: Non-Orthogonal Multiple Access (NOMA) techniques and Radio Resource Management (RRM) schemes. Specifically, NOMA transmits simultaneously several layered data flows so that the whole bandwidth is used throughout the entire time to deliver more than one service simultaneously. Then, RRM schemes provide efficient management and distribution of radio resources among network users. Although NOMA techniques and RRM schemes can be very advantageous in all use cases, this thesis focuses on making contributions in eMBB and URLLC environments and proposing solutions to communications that are expected to be relevant in 6G

Proceedings of the Third International Mobile Satellite Conference (IMSC 1993)

Satellite-based mobile communications systems provide voice and data communications to users over a vast geographic area. The users may communicate via mobile or hand-held terminals, which may also provide access to terrestrial cellular communications services. While the first and second International Mobile Satellite Conferences (IMSC) mostly concentrated on technical advances, this Third IMSC also focuses on the increasing worldwide commercial activities in Mobile Satellite Services. Because of the large service areas provided by such systems, it is important to consider political and regulatory issues in addition to technical and user requirements issues. Topics covered include: the direct broadcast of audio programming from satellites; spacecraft technology; regulatory and policy considerations; advanced system concepts and analysis; propagation; and user requirements and applications

Heterogeneous wireless networks for smart cities

In the near future, a world of smart cities is envisioned in which many devices equipped with sensors and communication interfaces can be used to collect and share data in order to derive maps or infer information on some parameter of interest. Wireless technologies are enabling this smart city paradigms, where many items are networked for the growth of society. This scenario opens new challenges to wireless network designers, with new performance metrics, coverage and privacy needs, as well as the need for a tighter integration of different networks. This is the fundamental concept of Heterogeneous Networks. Enclosing humans in the loop, through crowdsensing techniques, will dramatically increase the amount of data available for the mapping process, with obvious benefits in terms of the resulting accuracy. On the other hand, the huge amount of data generated represents also a challenge that, along with the irregular, uncontrollable, spatial distribution of measurements represent serious challenges to be addressed. Another important aspect of smart cities scenarios is represented by vehicular networks. Several technologies have been proposed to address such application. Among the others, an interesting solution is provided by Visible Light Communications (VLC). Based on the use of the light emission diodes (LEDs) that are already available on the majority of vehicles, VLC would enable short range communication in large, unlicensed, and uncongested bands with limited costs. In the framework of smart cities scenarios, my research activity aimed at formulating and solving some of the issues arising from the envisioned challenging services, with both analytical and simulation-based approaches

Dual port microstrip patch antennas and circuits with high interport isolation for in-band full duplex (IBFD) wireless applications

In-Band Full Duplex (IBFD) is one effective way to increase the spectral efficiency and the throughput of wireless communication systems by transmitting and receiving simultaneously on the same frequency band but the coupling (called Self Interference or SI) of transmit signal to its receiver is one major problem. IBFD operation can be realized successfully by suppressing this coupling or Self Interference (SI). The required amount of SI cancellation depends on the power and bandwidth of transmitted signal. Generally, the SI should be suppressed to RF transceiver noise floor. To achieve this amount of SI suppression, SI suppression mechanism is normally implemented at three stages across the IBFD transceiver and they are known as antenna cancellation, RF/analog cancellation and digital base-band cancellation. Most of the SI suppression is achieved at antenna stage to relax the required amount of SI cancellation at the rest of two stages .Thus, a dual port microstrip patch antenna with very high port to port RF isolation is required in addition to digital self interference cancellation techniques to enable simultaneous transmit and receive wireless operation at same carrier frequency using single antenna for full duplex radio transceivers. The objective of my research work presented in this dissertation is to design, implement and measure dual port microstrip patch antennas which deploy different feeding techniques along with Self Interference Cancellation (SIC) circuits to get high interport isolation to enable such antennas for realization of IBFD wireless operation using single/shared antenna architecture. The goal is to achieve high interport isolation for dual port antenna with minimum effect on radiation performance of antennas