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Cássio Gonçalves do Regohttp://lattes.cnpq.br/4951179285879076Dinael Guevara IbarraGlaucio Lopes RamosLuiz Alencar Reis da Silva MelloAlberto Resende De ContiFernando José da Silva Moreirahttp://lattes.cnpq.br/6222846532551052Diego Andrés Parada Rozo2023-07-11T18:34:37Z2023-07-11T18:34:37Z2023-05-19http://hdl.handle.net/1843/56079O desenvolvimento de modelos de propagação para a precisa previsão de cobertura de ondas de rádio é um desafio para os pesquisadores. A maior dificuldade na construção desses modelos é a adequada caracterização das condições não homogêneas dos ambientes (variações atmosféricas, caracterização eletromagnética de superfícies, perfis irregulares de terreno, etc.), pois estas afetam a radiopropagação e produzem diversos fenômenos de espalhamento. Esta tese centra-se na exploração da técnica Ray Tracing (RT) e do algoritmo numérico Split-Step Fourier Transform Parabolic Equation (SSPE). A escolha desses métodos explica-se pelo fato de ambos serem algoritmos de modelagem de propagação eletromagnética rápidos, robustos e promissores para incluir a influência das condições não homogêneas dos ambientes em suas soluções. Esta pesquisa apresenta um algoritmo de radiopropagação baseado na técnica RT que combina um modelo multipercurso modificado para perfis de gradiente de refratividade constante e a Teoria Uniforme de Difração (UTD). Uma nova formulação é proposta para analisar a reflexão no solo das trajetórias dos raios em função da refratividade atmosférica. Paralelamente, o método Discrete Mixed Fourier Transform (DMFT) é incluído no algoritmo SSPE, tornando-se uma abordagem DMFTSSPE para resolver problemas de radiopropagação com impedância de superfície como condição de contorno. Inicialmente, este trabalho avalia os algoritmos obtidos em casos canônicos e em um cenário misto, sob condições de gradiente de refratividade constante, perfis de terreno com perdas e usando bandas de frequências projetadas para aplicações 5G. Com base nos resultados obtidos, é possível afirmar que ambos os métodos têm um comportamento semelhante em todos os casos testados. Posteriormente, os dois modelos de propagação obtidos foram aplicados para prever a cobertura e caracterizar o canal de rádio em cenários suburbanos da região andina e da floresta do Pacífico, ambos na Colômbia. Nestes casos realísticos os resultados mostraram a similaridade das curvas de pathloss obtidas com ambas as abordagens. Portanto, os dois modelos de radiopropagação apresentados nesta tese são projetados como ferramentas úteis de previsão de cobertura em áreas remotas da geografia colombiana. Ao longo deste trabalho, o método DMFT-SSPE e uma proposta modificada de RT com efeito de refratividade atmosférica são apresentados como alternativas que garantem resultados razoáveis, demonstrando precisão e notável eficiência computacional para analisar a propagação de ondas de rádio.The development of propagation models for accurate radiowave coverage prediction is a challenge for researchers and radio engineers. The greatest difficulty in the construction of these models is the appropriated characterization of the factors that affect the radiowave propagation, such as the non-homogeneous conditions of realistic environments (atmospheric variations, electromagnetic characterization of surfaces, irregular terrain profiles, etc.), since they produce several scattering phenomena. This thesis focuses on the exploration of the Ray Tracing (RT) technique and the Split-Step Fourier Transform Parabolic Equation (SSPE) numerical algorithm. The choice of these methods can be explained by the fact that both are fast and robust electromagnetic propagation modeling algorithms, widely used, and promising to include within their solutions the influence of the different non-homogeneous environments conditions. This research presents a radiopropagation algorithm based on RT technique that combines a modified multipath model for constant refractivity gradient profiles and the Uniform Theory of Diffraction (UTD). A novel formulation is proposed for calculation and ground-reflection analysis of ray paths depending on atmospheric refractivity. In paralell, the Discrete Mixed Fourier Transform (DMFT) method is included into the SSPE algorithm, becoming a DMFT-SSPE approach to solve radio propagation problems over surfaces with impedance boundary conditions. This work proposes comparative studies with the purpose of validating the proposed formulation for modified RT, and evaluating the DMFT-SSPE implementation. Initially, the algorithms introduced herein were evaluated in canonical cases and a mixed scenario, under conditions of constant refractivity gradient, lossy terrain profiles and using the frequency bands projected for 5G applications. Taking into account the results obtained, it is possible to affirm that both methods have a similar behavior for all the cases tested. A remarkable case study was the application of the two algorithms in Colombian environments, which present challenging conditions for propagation modelling. The propagation models obtained were applied to predict coverage and temporarily characterize the radio channel in suburban scenarios of the Andean region and the Pacific forest, at 5G frequency bands. The results of this case study showed the similarity of the pathloss curves obtained with both approaches. Therefore, the two radiopropagation models presented in this thesis, are project as useful coverage prediction tools in remote areas of the Colombian geography. Throughout this work, the DMFT-SSPE method and a modified RT proposal with atmospheric refractivity effect, are presented as alternatives that guarantee reasonable results, demonstrating precision and remarkable computational efficiency to analyze radiowave propagation.CNPq - Conselho Nacional de Desenvolvimento Científico e TecnológicoengUniversidade Federal de Minas GeraisPrograma de Pós-Graduação em Engenharia ElétricaUFMGBrasilENG - DEPARTAMENTO DE ENGENHARIA ELÉTRICAEngenharia elétricaOndas de rádio - PropagaçãoSistemas de comunicação sem fioVelocidadeAlgoritmosTelecomunicaçõesRaiosRefraçãoEM propagationRT tecniquesAtmospheric refractivityMultipath modelSSPEDMFTUTDParabolic equation and ray tracing formulations for the development of radiowave propagation models in non-homogeneous mediainfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFMGinstname:Universidade Federal de Minas Gerais (UFMG)instacron:UFMGORIGINALParabolic equation and ray tracing formulations.pdfParabolic equation and ray tracing formulations.pdfapplication/pdf24469617https://repositorio.ufmg.br/bitstream/1843/56079/1/Parabolic%20equation%20and%20ray%20tracing%20formulations.pdf776479e91917769b6888a4f00b28ac11MD51LICENSElicense.txtlicense.txttext/plain; charset=utf-82118https://repositorio.ufmg.br/bitstream/1843/56079/2/license.txtcda590c95a0b51b4d15f60c9642ca272MD521843/560792023-07-11 15:34:37.728oai:repositorio.ufmg.br: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ório InstitucionalPUBhttps://repositorio.ufmg.br/oaiopendoar:2023-07-11T18:34:37Repositório Institucional da UFMG - Universidade Federal de Minas Gerais (UFMG)false
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