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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.
61

Modulador do sistema ATSC 3.0 usando Gnuradio Companion

Dionísio, Victor Morales 07 August 2017 (has links)
Submitted by Marta Toyoda (1144061@mackenzie.br) on 2018-02-07T23:34:13Z No. of bitstreams: 2 VICTOR MORALES DIONISIO.pdf: 15019971 bytes, checksum: cc45d6dd4e5209047a4c19cbfbe5eb00 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Paola Damato (repositorio@mackenzie.br) on 2018-02-22T13:35:18Z (GMT) No. of bitstreams: 2 VICTOR MORALES DIONISIO.pdf: 15019971 bytes, checksum: cc45d6dd4e5209047a4c19cbfbe5eb00 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-02-22T13:35:18Z (GMT). No. of bitstreams: 2 VICTOR MORALES DIONISIO.pdf: 15019971 bytes, checksum: cc45d6dd4e5209047a4c19cbfbe5eb00 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-08-07 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Fundo Mackenzie de Pesquisa / This paper presents the characteristics of two recent technologies on the scienti c and telecommunications community: the Advanced Television Systems Committee (ATSC) 3.0; the Software De ned Radio (SDR). Later, the usage of the three is studied by developing the modulator of the ATSC 3.0 system with SDR technique and the GNURadio Companion (GRC). In order to prove the integrity of the modulator implementation, the transmitted signal is tested with the Dektec receiver, composed by the DTA-2131 hardware and the Atsc3Xpress software. All the codes are developed in C++ language and the tests made in GRC. Such tests prove the integrity of the implementation since the receiver was able to demodulate the signal correctly, and that the SDR platform is a suitable tool for prototyping and researching digital TV transmission systems. / Este projeto apresenta as definições e características de duas tecnologias recentes na comunidade científica e de telecomunicações: o Advanced Television Systems Committee (ATSC) 3.0; o Rádio Definido por Software, do inglês Software Defined Radio (SDR). Posteriormente, investiga a combinação delas, desenvolvendo um modulador do sistema ATSC 3.0 por meio da técnica de SDR, utilizando o software GNURadio Companion (GRC). Com o intuito de comprovar a integridade da implementação do modulador, o sinal _e testado com o receptor, composto pelo hardware DTA-2131 e software Atsc3Xpress da Dektec. O desenvolvimento do sistema _e feito por meio de algoritmos computacionais em linguagem C++ e os testes são feitos no GRC. Tais testes comprovam a integridade da implementação uma vez que o receptor foi capaz de demodular o sinal corretamente, e que a plataforma de SDR _e uma ferramenta adequada para prototipagem e pesquisa de sistemas de transmissão de TV digital.
62

Lightweight Middleware for Software Defined Radio (SDR) Inter-Components Communication

Putthapipat, Pasd 11 April 2013 (has links)
The ability to use Software Defined Radio (SDR) in the civilian mobile applications will make it possible for the next generation of mobile devices to handle multi-standard personal wireless devices and ubiquitous wireless devices. The original military standard created many beneficial characteristics for SDR, but resulted in a number of disadvantages as well. Many challenges in commercializing SDR are still the subject of interest in the software radio research community. Four main issues that have been already addressed are performance, size, weight, and power. This investigation presents an in-depth study of SDR inter-components communications in terms of total link delay related to the number of components and packet sizes in systems based on Software Communication Architecture (SCA). The study is based on the investigation of the controlled environment platform. Results suggest that the total link delay does not linearly increase with the number of components and the packet sizes. The closed form expression of the delay was modeled using a logistic function in terms of the number of components and packet sizes. The model performed well when the number of components was large. Based upon the mobility applications, energy consumption has become one of the most crucial limitations. SDR will not only provide flexibility of multi-protocol support, but this desirable feature will also bring a choice of mobile protocols. Having such a variety of choices available creates a problem in the selection of the most appropriate protocol to transmit. An investigation in a real-time algorithm to optimize energy efficiency was also performed. Communication energy models were used including switching estimation to develop a waveform selection algorithm. Simulations were performed to validate the concept.
63

Efficient wireless transmission supporting internet of things

Ghasemiahmadi, Mohammad 19 December 2017 (has links)
The promise of Internet of Things (IoT) and mass connectivity has brought many applications and along with them many new challenges to be solved. Recognizing sensor networks as one of the main applications of IoT, this dissertation focuses on solutions for IoT challenges in both single-hop and multi-hop communications. In single-hop communications, the new IEEE 802.11ah and its Group Synchronized Distribution Coordination Function (GS-DCF) is studied. GS-DCF categorized nodes in multiple groups to solve the channel contention issue of dense networks. An RSS-Based grouping strategy is proposed for the hidden terminal problem that can arise in infrastructure-based single hop communications. For multi-hop communications, Physical Layer Network Coding (PNC) is studied as a robust solution for multi-hop packet exchange in linear networks. Focusing on practical and implementation issues of PNC systems, different challenges have been addressed and a Software Defined Radio (SDR) PNC system based on USRP devices is proposed and implemented. Finally, extensive simulation and experimental results are presented to evaluate the performance of the proposed algorithms in comparison with currently used methods. / Graduate
64

Proof-of-Concept Prototype of Deep Learning Based Channel Mapping Using An Autonomous Channel Measurement System

January 2020 (has links)
abstract: The recent increase in users of cellular networks necessitates the use of new technologies to meet this demand. Massive multiple input multiple output (MIMO) communication systems have great potential for increasing the network capacity of the emerging 5G+ cellular networks. However, leveraging the multiplexing and beamforming gains from these large-scale MIMO systems requires the channel knowlege between each antenna and each user. Obtaining channel information on such a massive scale is not feasible with the current technology available due to the complexity of such large systems. Recent research shows that deep learning methods can lead to interesting gains for massive MIMO systems by mapping the channel information from the uplink frequency band to the channel information for the downlink frequency band as well as between antennas at nearby locations. This thesis presents the research to develop a deep learning based channel mapping proof-of-concept prototype. Due to deep neural networks' need of large training sets for accurate performance, this thesis outlines the design and implementation of an autonomous channel measurement system to analyze the performance of the proposed deep learning based channel mapping concept. This system obtains channel magnitude measurements from eight antennas autonomously using a mobile robot carrying a transmitter which receives wireless commands from the central computer connected to the static receiver system. The developed autonomous channel measurement system is capable of obtaining accurate and repeatable channel magnitude measurements. It is shown that the proposed deep learning based channel mapping system accurately predicts channel information containing few multi-path effects. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2020
65

Development of Software-Defined Multichannel Receiver for Equatorial Atmosphere Radar (EAR) / ソフトウェア無線機を用いた赤道大気レーダー(EAR)用多チャンネル受信機の開発

Nor, Azlan bin Mohd Aris 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第22590号 / 情博第727号 / 新制||情||124(附属図書館) / 京都大学大学院情報学研究科通信情報システム専攻 / (主査)教授 橋口 浩之, 教授 山本 衛, 准教授 村田 英一 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM
66

Heterogeneous integration of optical wireless communications within next generation networks

Rahaim, Michael 28 October 2015 (has links)
Unprecedented traffic growth is expected in future wireless networks and new technologies will be needed to satisfy demand. Optical wireless (OW) communication offers vast unused spectrum and high area spectral efficiency. In this work, optical cells are envisioned as supplementary access points within heterogeneous RF/OW networks. These networks opportunistically offload traffic to optical cells while utilizing the RF cell for highly mobile devices and devices that lack a reliable OW connection. Visible light communication (VLC) is considered as a potential OW technology due to the increasing adoption of solid state lighting for indoor illumination. Results of this work focus on a full system view of RF/OW HetNets with three primary areas of analysis. First, the need for network densication beyond current RF small cell implementations is evaluated. A media independent model is developed and results are presented that provide motivation for the adoption of hyper dense small cells as complementary components within multi-tier networks. Next, the relationships between RF and OW constraints and link characterization parameters are evaluated in order to define methods for fair comparison when user-centric channel selection criteria are used. RF and OW noise and interference characterization techniques are compared and common OW characterization models are demonstrated to show errors in excess of 100x when dominant interferers are present. Finally, dynamic characteristics of hyper dense OW networks are investigated in order to optimize traffic distribution from a network-centric perspective. A Kalman Filter model is presented to predict device motion for improved channel selection and a novel OW range expansion technique is presented that dynamically alters coverage regions of OW cells by 50%. In addition to analytical results, the dissertation describes two tools that have been created for evaluation of RF/OW HetNets. A communication and lighting simulation toolkit has been developed for modeling and evaluation of environments with VLC-enabled luminaires. The toolkit enhances an iterative site based impulse response simulator model to utilize GPU acceleration and achieves 10x speedup over the previous model. A software defined testbed for OW has also been proposed and applied. The testbed implements a VLC link and a heterogeneous RF/VLC connection that demonstrates the RF/OW HetNet concept as proof of concept.
67

Exploration into the Use of a Software Defined Radio as a Low-Cost Radar Front-End

Monk, Andrew Michael 23 November 2020 (has links)
Inspection methods for satellites post-launch are currently expensive and/or dangerous. To address this, BYU, in conjunction with NASA, is designing a series of small satellites called CubeSATs. These small satellites are designed to be launched from a satellite and to visually inspect the launching body. The current satellite revision passively tumbles through space and is appropriately named the passive inspection cube satellite (PICS). The next revision actively maintains translation and rotation relative to the launching satellite and is named the translation, rotation inspection cube satellite (TRICS). One of the necessary sensors aboard this next revision is the means to detect distance. This work explores the feasibility of using a software defined radio as a small, low-cost front end for a ranging radar to fulfill this need. For this work, the LimeSDR-Mini is selected due to its low-cost, small form factor, full duplex operation, and open-source hardware/software. Additionally, due to the the channel characteristics of space, the linear frequency modulated continuous-wave (LFMCW) radar is selected as the radar architecture due to its ranging capabilities and simplicity. The LFMCW radar theory and simulation are presented. Two programming methods for the LimeSDR-Mini are considered: GNU Radio Companion and the pyLMS7002Soapy API. GNU Radio Companion is used for initial exploration of the LimeSDR-Mini and confirms its data streaming (RX and TX) and full duplex capabilities. The pyLMS7002Soapy API demonstrates further refined control over the LimeSDR-Mini while providing platform independence and deployability. This work concludes that the LimeSDR-Mini is capable of acting as the front end for a ranging radar aboard a small satellite provided the pyLMS7002Soapy API is used for configuration and control. GNU Radio Companion is not recommended as a programming platform for the LimeSDR-Mini and the pyLMS7002Soapy API requires further research to fine tune the SDR's performance.
68

Study to improve measurement accuracy and resolution of atmospheric radars / 大気レーダーの測定精度と分解能の向上に関する研究

Gan, Tong 24 November 2015 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第19385号 / 情博第595号 / 新制||情||104(附属図書館) / 32399 / 新制||情||104 / 京都大学大学院情報学研究科通信情報システム専攻 / (主査)教授 山本 衛, 教授 津田 敏隆, 教授 佐藤 亨 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM
69

Sparse Aperture Measurement in a Non-Ideal Semi-Anechoic Chamber

Vinci, Joseph J. 30 May 2019 (has links)
No description available.
70

Time Division Duplex (TDD) Multi-User Multiple-Input, Multiple-Output (MU-MIMO) Mobile Ad-Hoc Network(MANET)

Peters, Gavin M. 28 October 2019 (has links)
No description available.

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