Dissertations / Theses on the topic 'Indoor propagation models'

Indoor use of wireless systems poses one of the biggest design challenges. It is difficult to predict the propagation of a radio frequency wave in an indoor environment. To assist in deploying the above systems, characterization of the indoor radio propagation channel is essential. The contributions of this work are two-folds. First, in order to build a model, extensive field strength measurements are carried out inside two different buildings. Then, path loss exponents from log-distance path loss model and standard deviations from log-normal shadowing, which statistically describe the path loss models for a different transmitter receiver separations and scenarios, are determined. The purpose of this study is to characterize the indoor channel for 802.11 wireless local area networks at 2.4 GHz frequency. This thesis presents a channel model based on measurements conducted in commonly found scenarios in buildings. These scenarios include closed corridor, open corridor, classroom, and computer lab. Path loss equations are determined using log-distance path loss model and log-normal shadowing. The chi-square test statistic values for each access point are calculated to prove that the observed fading is a normal distribution at 5% significance level. Finally, the propagation models from the two buildings are compared to validate the generated equations.

The report treats the development and evaluation of a three dimensional user distribution model for a real network simulator. The simulator is used to create realistic predictions of real networks with the use of high resolution maps including a building data base and network data and also an advanced radio model for LTE. Previously all simulations have been performed with a two dimensional user distribution, i.e. all users situated on the ground level. Since it is considered plausible that many LTE users will be indoors in buildings with multiple floors, several three dimensional user distribution models with users not only on the ground floor but also on the higher floors has been developed and implemented in the simulator. The models all account for the change in path loss and SINR to be expected and have been compared in computational time and credibility. The simulations show that by the use of such a three dimensional model there is a significant improvement at low loads but at high loads the interference becomes dominant and the results show a deterioration and approaches the results of the ordinary two dimensional model. The seventh and last model to be investigated shows a desirable computational speed that still does not compromise too much with the accuracy and detailing of the model and is therefore recommended for normal use.

An extensive radio wave propagation measurement campaign was conducted at 1.3 GHz and 4.0 GHz inside four buildings, including a sports arena, a modern closed-plan office building, and two dissimilar, open-plan factories. Measurements were recorded at 57 locations using base station antenna heights of 1.7 meters and 4.0 meters. Results were obtained for mean and maximum excess delay, rms delay spread, time delay jitter, differential delay jitter, and path loss through analyses of impulse response estimates, which were obtained via repetitive 5 ns probing pulses. The effects of frequency, antenna height, topography (line-of-sight or obstructed direct path), and building environment on delay spread and path loss are quantified. Results indicate that, on average, the frequencies and antenna heights used in this study have minimal impact on rms delay spread and path loss. However, topography and building environment significantly affect these parameters. RMS delay spread values as high as 230 ns were observed in open plan factories. Computed path loss power law exponents are 1.84 and 2.35 for line-of-sight and obstructed topographies, respectively. A second campaign was conducted to determine the effects of antenna directivity and polarization on propagation parameters. On average, line-of-sight indoor channels offer 8 dB of cross-polarization discrimination, whereas obstructed environments offer less than 3 dB. Directional antennas provide a significant reduction in rms delay spread over omni-directional antennas. In line-of-sight environments, circular polarization provides an additional delay spread reduction.<br>Master of Science

At present, the current 4G systems provide a universal platform for broadband mobile services; however, mobile traffic is still growing at an unprecedented rate and the need for more sophisticated broadband services is pushing the limits on current standards to provide even tighter integration between wireless technologies and higher speeds. This has led to the need for a new generation of mobile communications: the so-called 5G. Although 5G systems are not expected to penetrate the market until 2020, the evolution towards 5G is widely accepted to be the logical convergence of internet services with existing mobile networking standards leading to the commonly used term “mobile internet” over heterogeneous networks, with several Gbits/s data rate and very high connectivity speeds. Therefore, to support highly increasing traffic capacity and high data rates, the next generation mobile network (5G) should extend the range of frequency spectrum for mobile communication that is yet to be identified by the ITU-R. The mm-wave spectrum is the key enabling feature of the next-generation cellular system, for which the propagation channel models need to be predicted to enhance the design guidance and the practicality of the whole design transceiver system. The present work addresses the main concepts of the propagation channel behaviour using ray tracing software package for simulation and then results were tested and compared against practical analysis in a real-time environment. The characteristics of Indoor-Indoor (LOS and NLOS), and indoor-outdoor (NLOS) propagations channels are intensively investigated at four different frequencies; 5.8 GHz, 26GHz, 28GHz and 60GHz for vertical polarized directional, omnidirectional and isotropic antennas patterns. The computed data achieved from the 3-D Shooting and Bouncing Ray (SBR) Wireless Insite based on the effect of frequency dependent electrical properties of building materials. Ray tracing technique has been utilized to predict multipath propagation characteristics in mm-wave bands at different propagation environments. Finally, the received signal power and delay spread were computed for outdoor-outdoor complex propagation channel model at 26 GHz, 28 GHz and 60GHz frequencies and results were compared to the theoretical models.

L’évolution constante des technologies sans fil telles que le Wi-Fi, les normes de réseaux mobiles ou d’objets connectés, a donné naissance à de nouvelles applications et usages. Les possibilités offertes par cette multitude d’alternatives sont exploitées par les réseaux sans fil hétérogènes qui, en combinant au sein d’un réseau unique plusieurs technologies, permettent aux utilisateurs d’accéder à des services complémentaires de façon transparente. Cependant, pour bénéficier pleinement de ces avantages, plusieurs défis techniques sont à relever. L’un d’eux est relatif au déploiement de ces réseaux multi- technologies. En pratique, cette tâche s’appuie sur des règles et outils d’ingénierie afin de réaliser une planification optimale. Dans ce contexte, un objectif de la thèse a été d’établir des modèles sur lesquels peuvent se baser les outils d’ingénierie radio afin d’optimiser le déploiement de réseau locaux sans fil multi- technologies.Il s’agit principalement de calibrer des modèles de propagation pour l’estimation de couverture radio en environnement indoor résidentiel entre 800 MHz et 60 GHz; d’établir un modèle de débit pour l’estimation de capacité Wi-Fi en fonction du trafic montant et descendant; et de concevoir un modèle de résolution multi-objectif pour optimiser le positionnement de points d’accès opérant à 5 et 60 GHz. En complément, cette thèse a également proposé des recommandations pratiques visant à placer au mieux les points d’accès en phase de déploiement. Cela s’est fait par le biais d’études de sensibilité de couverture à divers facteurs, tels que l’environnement immédiat de l’émetteur ou encore la présence de personnes faisant obstruction<br>The constant evolution of wireless technologies such as Wi-Fi, mobile networks standards or IoT, has given rise to new applications and usages. The possibilities offered by this multitude of alternatives are exploited by heterogeneous wireless networks which, by combining within a single network several technologies, provide the users with a seamless access to complementary services. However, to take full advantage of these benefits, there are several technical issues to address. One of them is related to the deployment of these multi-technology networks. In practice, this task relies, most of the time, on radio network design software to achieve optimal planning. In such context, the main objective of this thesis is to establish models which can be used by radio network planning tools in order to the deployment of multi-technology wireless local area networks. This task has involved calibrating propagation models for radio coverage estimation, in residential indoor environments from 800 MHz to 60 GHz; developing a throughput model for Wi-Fi capacity estimation based on uplink and downlink traffic; and establishing a multi- objective resolution model to optimize the positioning of access points operating at 5 and 60 GHz. Moreover, this thesis also proposes practical recommendations for a better positioning of access points during deployment phases. This task has been achieved through coverage sensitivity studies to various factors, such as the transmitter surroundings or the presence of obstructing people

This paper deals with the propagation of waves. Here is the wavelength distribution according to the wavelength. It focuses on the UHF and SHF band in which IEEE802.11n operates. Contains model breakdown by cell type. Describes which propagation methods are dominant in the cell type. Several propagation patterns are presented, which are then modeled in Matlab environment.The models are then compared to experimental measurements.

Im Rahmen der seit ca. 1980 platzgreifenden Miniaturisierung wird es immer interessanter, kostengünstige miniaturisierte Funkgeräte für verschiedene Kommunikationszwecke auch in Gebäuden einzusetzen. Zu erwähnen sind hier vor allem moderne Funktelefone, zunehmend werden aber auch auch Funkstrecken zur Datenübertragung in der Industrie wie auch in privaten Haushalten eingesetzt. Funkübertragung in Gebäuden ist keineswegs unkritisch. Neben gewollten und unbeabsichtigten elektromagnetischen Emissionen stört vor allem die Streuung des elektromagnetischen Feldes an verschiedenartigen Objekten, die in Gebäuden in hoher Dichte vorhanden sind. Der Funkkanal im Gebäude wird in der Arbeit definiert und seine Berechnung in Antennen- und Ausbreitungsproblem aufgeteilt. Rotationssymmetrische Sende- und Empfangsantennen können so unabhängig vom Ausbreitungsproblem simuliert werden. Für die Antennen- und Ausbreitungssimulation wird je ein hybrides Zeitbereichsverfahren vorgestellt. Homogene Gebiete werden dabei mit der schnellen Diskreten Wellengleichung behandelt, Diskontinuitäten mit dem Yee-Schema diskretisiert. Die Verfahren werden unter Verwendung diskreter Feldoperatoren hergeleitet und in bezug auf Dispersion und Genauigkeit untersucht. Absorbierende Randbedingungen werden eingeführt und analysiert. Zur Verifikation der Antennensimulationsverfahren wurden Simulationen für Dipolantennen, eine Disconeantenne und eine koaxial gespeiste Monopolantenne durchgeführt und mit Meßdaten bzw. im Fall der Dipolantenne mit Ergebnissen eines anderen Simulationsverfahrens verglichen. In zwei Testszenarien wurden Transmissionsfaktoren von Funkkanälen in Gebäuden berechnet und Meßergebnissen gegenübergestellt. Die Übereinstimmung ist im Rahmen der für diese kritischen Simulationen zu erwartenden Genauigkeit gut. Die vorgestellten Zeitbereichsverfahren gestatten die Berechnung von Funkkanalimpulsantworten mit sehr hoher Zeitauflösung, wie sie in Forschung und Entwicklung benötigt werden. In Zukunft werden Zeitbereichssimulationen für Funkkanäle immer attraktiver werden, besonders dann, wenn die in der Vergangenheit beobachtete Leistungssteigerung bei Kleincomputern anhält. Doch auch mit heutigen Computern werden angemessen kurze Rechenzeiten bei sehr guten Ergebnissen erreicht.

Neste trabalho, modelos de pedestres, utilizados para simular a caracterização da radiopropagação em interiores de edifícios, são reproduzidos, analisados e comparados em diversos ambientes e com diferentes fluxos de pedestres. Estes modelos têm como base o método de traçado de raios (imagens), e se diferenciam em relação ao formato (lâmina, paralelepípedo e cilindro), constantes eletromagnéticas (material absorvente, condutor e dielétrico) e mecanismos de espalhamento de onda eletromagnética (difração, reflexão ou ambos) considerados sobre o pedestre. Para cada um dos modelos, um algoritmo foi criado e detalhado através da apresentação de equações e estrutura dos dados. A análise dos modelos foi realizada em duas etapas de comparação: uma com dados empíricos e outra entre parâmetros de caracterização do canal, como desvanecimentos e dispersão no tempo, obtidos através de simulações com cada tipo de modelo de pedestre. Dentre os vinte e nove modelos ensaiados, os resultados da análise mostraram que o pedestre modelado por um cilindro condutor é aquele que apresenta resultados mais satisfatórios.<br>In this work, pedestrian models, used to simulate characterization of indoor radio propagation are reproduced, analyzed and compared in different environments with different pedestrian flows. These models are based on the image ray-tracing method, and differs themselves on shape (plate, cylinder and cuboid), electromagnetic constant (absorber, conductive and dielectric materials) and considered spread mechanisms (diffraction, reflection, or both). For each model, an algorithm is created and detailed through the presentation of equations and data structure. The models analysis were made in two comparison steps: one with empirical data and the other with the environment characterization parameters, like fading and time spread, obtained through simulations of each pedestrian model. Within twenty nine models simulation, the results analysis show that the most satisfactory results are given by the model that considers the pedestrian as a conducting cylinder.

In the push for spectrum sharing and open spectrum access, the 3.5 GHz frequency band is under consideration for small cells and general Wireless Local Area Networks (WLAN) in the United States. The same band is beginning to see deployment in China, Japan, and South Korea, for the 4G Long Term Evolution (LTE) cellular standard to increase coverage and capacity in urban areas through small cell deployment. However, since the adoption of this band is new, there is a distinct shortage of propagation data and accurate channel modeling at 3.5 GHz in indoor environments. These models are necessary for cellular coverage planning and evaluating the performance and feasibility of wireless systems. This report presents the results of a fixed wireless channel measurement campaign at 3.5 GHz. Measurements were taken in environments typical of indoor wireless deployment: traditional urban indoor office, hallway, classroom, computer laboratory, and atrium areas, as well as within a hospital. Primarily Non Line of Sight (NLOS) experiments were carried out in areas with a controllable amount of partitions separating the transmitter and receiver in order to document material-based attenuation values. Indoor-to-outdoor measurements were carried out, focusing on attenuation due to common exterior building materials such as concrete, brick, wood, and reinforced glass. Documented metrics include large scale path loss, log-normal shadowing, and channel power delay profiles combined with delay spread characteristics for multipath analysis. The statistical multi-antenna diversity gain was evaluated to gauge the benefit of using multi-antenna systems in an indoor environment, which has much greater spatial diversity than an outdoor environment. Measurements were compared to indoor path loss models used for WLAN planning in the low GHz range to investigate the applicability of extending these models to 3.5 GHz.<br>Master of Science

In this thesis a theoretical model for indoor propagation in a straight corridor with adjacent rooms is developed and evaluated. One objective is to assess the effect of different conductivities and permittivities in the walls between rooms have on the power levels, in both the corridor and the rooms. Furthermore, a model of a leaky cable is proposed for which the corresponding propagation characteristics are evaluated and compared to that of a dipole antenna to assess if a leaky cable is a viable alternative for radio coverage in an indoor environment. In order to evaluate the model, a wideband measurement campaign has been conducted at 2.44 GHz with a 40 meter long leaky coaxial cable and two vertically polarized dipole antennas. The proposed model is based on the waveguide model in 2D, the mode matching method and cascade coupling of scattering matrices. A section of a corridor is modeled as waveguides with different cross section where one waveguide contains a dielectric medium which models the wall between two rooms. Mode matching is used to determine how the waveguide modes are coupled at the boundaries between the waveguides and the result is collected in a scattering matrix. Multiple corridor sections are then connected together, by cascade coupling the corresponding scattering matrices of each section, into a long corridor with adjacent rooms. Point sources are used to excite the waveguides as an approximation of dipole transmitting antennas. Moreover, the radiating slots in the leaky cable are modeled by multiple point sources that are phase and amplitude shifted in order to achieve the same radiation direction and longitudinal loss as the leaky cable. Finally, the inverse discreet Fourier transform is applied to the wideband electromagnetic field distribution in order to determine the propagation characteristics in the time domain. The results from the model are in good quantitative agreement with the measurement data, and it is shown that a leaky cable give a more even radio coverage in an office corridor compared to a dipole antenna, especially when the internal walls are highly reflective. Moreover, it is shown that the direct path is dominating for transmission between rooms with transparent walls, like plasterboard, while the main propagation path for highly reflective walls is along the corridor.

Les systèmes de localisations existants présentent des insuffisances au niveau desapplications en environnement indoor. Ces insuffisances se traduisent soit par la non-disponibilité des signaux (le GPS) dans ce type d'environnement, soit par leur manque de précision quand ils sont prévus à cet effet. Ces limites ont motivé la recherche de nouvelles techniques. Les transmissions Ultra-Large Bande (ULB) de par leur singularité en matière de précision et de faible puissance d'émission, s'avèrent être la meilleure réponse à la problématique ci-dessus. Nous avons donc choisi cette technique pour mettre au point un procédé de localisation endogène permettant d'assurer, avec précision, la continuité des services de localisation dans les environnements indoor. Ce procédé s'appuie sur la localisation en trois dimensions (3-D). Il utilise la technique temporelle de différenciation du temps d'arrivée (TDOA). Cette technique permet de mieux tirer profit de la bonne résolution temporelle de l'ULB et de pallier au problème de synchronisation entre l'émetteur et le récepteur. Deux techniques de transmission ULB ont été étudiées : la technique d'accès multiples par séquence directe (DS-CDMA) et la technique d'accès multiples par sauts temporels (TH-CDMA). Une autre étape importante de notre étude a été de développer un algorithme non-itératif de localisation en 3-D pour réduire le temps de calcul. En effet, l'utilisation d'un algorithme non-itératif permet d'optimiser les performances du système en termes de temps de calcul voire de coûts de consommation énergétique. Après l'étude théorique des différents blocs du système, le système a été tout d'abord simulé dans le canal Gaussien (AWGN) et les canaux IEEE.802.15.4a indoor. Il a été ensuite testé dans différents environnements réels de types laboratoires. Les résultats obtenus démontrent que l'utilisation des techniques de transmission basées sur la technologie radio impulsionnelle ULB permet d'obtenir un système de localisation en 3-D avec une précision centimétrique pour les applications indoor.

The objective of this work is to enhance the awareness of the indoor propagation behaviour, by a set of investigations including simulations and measurements. These investigations include indoor propagation behaviour, local mean power estimation, proposing new indoor path loss model and introducing a case study on 60 GHz propagation in indoor environments using ray tracing and measurements. A summary of propagation mechanisms and manifestations in the indoor environment is presented. This comprises the indoor localization techniques using channel parameters in terms of angle of arrival (AOA), time of arrival (TOA) and received signal strength (RSS). Different models of path loss, shadowing and fast fading mechanisms are explored. The concept of MIMO channels is studied using many types of deterministic channel modelling such as Finite Difference Time Domain, Ray tracing and Dominant path model. A comprehensive study on estimating local average of the received signal strength (RSS) for indoor multipath propagation is conducted. The effect of the required number of the RSS data and their Euclidian distances between the neighbours samples are investigated over 1D, 2D and 3D configurations. It was found that the effect of fast fading was reduced sufficiently using 2D horizontal’s arrangement with larger spacing configuration. A modified indoor path loss prediction model is presented namely effective wall loss model (EWLM). The modified model with wall correction factors is compared to other indoor path loss prediction models using simulation data (for 2.4, 5, 28, 60 and 73.5 GHz) and real-time measurements (for 2.4 and 5 GHz). Different operating frequencies and antenna polarizations are considered to verify the observations. In the simulation part, EWLM shows the best performance among other models. Similar observations were recorded from the experimental results. Finally, a detailed study on indoor propagation environment at 60 GHz is conducted. The study is supported by Line of Sight (LoS) and Non-LoS measurements data. The results were compared to the simulated ones using Wireless-InSite ray tracing software. Several experiments have confirmed the reliability of the modelling process based on adjusted material properties values from measurements.

In this thesis electromagnetic wave propagation is investigated in an indoor environment. The indoor environment is a furnished office building with corridors, corners and rooms. Particularly, there is an atrium through the building in the center. For the study there were measurements available from real building in the 2.1 GHz frequency band. One objective is to design a propagation model that should be simple but reflect the trend of the propagation measurements. Furthermore, a system performance evaluation is carried out based on the implemented model. The proposed 3D model is a combination of the Free Space Path Loss model, the Keenan-Motley model and the recursive diffraction model. The channel predictions from the 2D Keenan-Motley algorithm are quite different from the measurements. Therefore, the 3D Keenan-Motley algorithm is designed to depict the atrium effect and speed up the simulation at the same time. Besides a buttery radiation diagram is created to mimic Kathrein 80010709 antenna installed in the building. Finally, a diffracted path is added to improve the received signal strength for the users around the atrium areas. With all the above procedures, the final results from the model are in good quantitative agreement with the measurement data. With the implemented propagation model, a further analysis of the system performance on the Distributed Antenna System (DAS) is performed. A comparison for the system capacity between the closed building and the atrium building is conducted, showing that the former one benefits more when the number of the cells increases. The reason is the atrium cells suffer severe interference from neighbor cells during high traffic demand scenarios. Then some further cell configurations show that the number of the cells, the geometry performance and the balance of the user fraction should be considered to improve the system capacity.

To achieve the concrete aim of improving the positioning accuracy for large-scale indoor space in this thesis, we propose a weighted Gaussian and Mean hybrid filter (G-M filter) to obtain the G-M mean of received signal strength indicator (RSSI) measurements, which is implemented by taking the practically experimental measurements of received signal strength indicator and analyzing the characteristics of received signal strength indicator. Meanwhile, various path loss models have been utilized to estimate the separation between the transmitting antenna and the receiver (T-R separation) by calculating the G-M mean of received signal strength indicator, therefore, a dynamic-parameter path loss model has been proposed which can be appropriate to enhance the accuracy of estimated T-R separation and accurately describe the indoor position. Moreover, an improved fingerprint positioning has been proposed as the basic method combined with our tetrahedral trilateration scheme to reduce the positioning error of a large-scale 3D indoor space which can achieve the average localization error of 1.5 meters.

Made available in DSpace on 2016-04-04T18:31:30Z (GMT). No. of bitstreams: 1 RINA GRACIELA RONDON GONZALEZ.pdf: 1534454 bytes, checksum: 58f56e565eb9e4082c5b978ceee457f4 (MD5) Previous issue date: 2009-12-18<br>Due to the increasing demand for services related to wireless networks, such as video, voice and video conferencing and to the concern of telecommunications companies to meet this demand efficiently, the planning of a wireless link becomes very important. Since the propagation of a signal over a wireless network is not driven, it can suffer attenuation caused by obstacles in the medium during its transfer from the transmitting equipment to the receiver, varying the signal strength of the transmission in each area covered. For this reason, in order to plan a wireless network, the characteristics of the environment and infrastructure through which the signal will travel, needs to be taken into account, so it is possible to get the real value of the received power at each required point. Furthermore, since the prediction of the signal?s attenuation in different places, taking into account the impact caused by each mentioned factor in its degradation, can be considered a complex process, it is necessary to use a model that not only considers the characteristics of the medium but also relates these factors in a simple manner allowing to measure the signal?s attenuation caused by the barriers founded in the environment. The Shadowing Signal Propagation model allows the characterization of the attenuation caused by the environment through the ? parameter present in this model. On the other hand, the Fuzzy Logic provides a form of approximate reasoning that allows the treatment of problems with incomplete, vague and imprecise information. Also, it offers a simple way to obtain a possible solution for a problem using the heuristic knowledge about a particular situation. In this way, the Fuzzy Logic can be an useful tool for calculating the ? parameter of the Shadowing Signal Propagation model, making possible to obtain ? values that characterize the attenuation of the environment in study. In this context, this work focuses on the analysis of signal?s attenuation in indoor environments using fuzzy logic.<br>Devido ? crescente demanda dos servi?os sobre redes sem fio, como v?deo, voz e v?deo confer?ncia e ? preocupa??o das companhias de telecomunica??es em atender esta demanda de forma eficiente, torna-se de fundamental import?ncia o planejamento de um enlace sem fio. Dado que a propaga??o de um sinal em uma rede sem fio n?o ? guiada, esta pode sofrer atenua??o causada pelos obst?culos encontrados no meio durante o seu percurso desde o equipamento transmissor at? o receptor, variando a pot?ncia do sinal da transmiss?o em cada ambiente percorrido. Por este motivo, para fazer o planejamento da rede ? necess?rio que sejam consideradas as caracter?sticas do ambiente e infra-estrutura por onde o sinal vai trafegar de modo que seja poss?vel obter o valor real da pot?ncia recebida em cada ponto do trajeto. Uma vez que a predi??o da atenua??o do sinal em diferentes ambientes, contemplando o impacto relacionado a cada fator que contribui com sua degrada??o, constitui-se em processo bastante complexo, existe a necessidade de utiliza??o de um modelo que al?m de contemplar as caracter?sticas do meio possa relacionar os fatores acima mencionados de uma forma simples de modo a permitir a determina??o da atenua??o do sinal causada pelas barreiras localizadas no meio. O Modelo de Propaga??o do Sinal de Shadowing permite caracterizar a atenua??o gerada pelo meio, atrav?s do par?metro ? presente na equa??o deste modelo. Por outro lado, a L?gica Nebulosa apresenta uma forma de racioc?nio aproximado que permite o tratamento de problemas com informa??es incompletas, vagas e imprecisas. Tamb?m, oferece uma forma simples de inferir uma poss?vel solu??o para um problema usando o conhecimento heur?stico sobre determinada situa??o. Neste sentido, a L?gica Nebulosa resulta em uma ferramenta ?til para o c?lculo do par?metro ? do Modelo de Propaga??o do Sinal de Shadowing posibilitando a obten??o de valores de ? que caracterizem com maior especifica??o a atenua??o do ambiente em estudo. Neste contexto, o presente trabalho trata da an?lise da atenua??o do sinal em ambientes indoor usando l?gica nebulosa.

Indoor/Outdoor Location of Cellular Handsets Based on Received Signal Strength Jian Zhu 123 pages Directed by Dr. Gregory D. Durgin Accurate geo-location is an important emerging technology for public safety, commercial use, and military application. Especially, in the United States, the wireless Enhanced 911 (E911) rules by the Federal Communication Commission (FCC) seek to provide 911 dispatchers with additional information on wireless 911 calls. This dissertation presents a novel technique for indoor/outdoor location of cellular handsets based on received signal strength (RSS) measurements taken by a cellular handset of the surrounding base stations. RSS location accuracy for different environments is studied as a function of base station separation distance, cell sector density, measurement density, radio propagation environment, and accuracy of measurement. The analytical and experimental results in this thesis serve as a guideline for the accuracy of RSS signature location technology under different conditions. Accurate outdoor to indoor penetration models are proposed and validated for dense urban areas by introducing pseudo-transmitters to simulate the wave-guiding effects in urban canyon environments. A set of location algorithms is developed to improve location accuracy. Furthermore, an algorithm to discriminate between indoor and outdoor users is proposed and validated. The research results demonstrate the feasibility of RSS location techniques to meet the FCCs requirements for E911 accuracy in urban and semi-urban environments. The techniques remain accurate for indoor handsets. The results also suggest that a hybridization of the handset-based GPS method and the RSS signature method may prove to be the most effective solution for locating handsets across a range of environments; including rural, suburban, dense urban, and indoor.

The statistics of the amplitude, time and angle of arrival of multipaths in an indoor environment are all necessary components of multipath models used to simulate the performance of spatial diversity in receive antenna configurations. The model presented by Saleh and Valenzuela, was added to by Spencer et. al., and included all three of these parameters for a 7 GHz channel. A system was built to measure these multipath parameters at 2.4 GHz for multiple locations in an indoor environment. Another system was built to measure the angle of transmission for a 6 GHz channel. The addition of this parameter allows spatial diversity at the transmitter along with the receiver to be simulated. The process of going from raw measurement data to discrete arrivals and then to clustered arrivals is analyzed. Many possible errors associated with discrete arrival processing are discussed along with possible solutions. Four clustering methods are compared and their relative strengths and weaknesses are pointed out. The effects that errors in the clustering process have on parameter estimation and model performance are also simulated.

Made available in DSpace on 2014-12-17T14:55:26Z (GMT). No. of bitstreams: 1 FranciscoAA_Capa_ate_11.pdf: 7331054 bytes, checksum: 95b093e73afc9c2e5df63a5d0c5b2c6b (MD5) Previous issue date: 2005-07-06<br>A 2.5D ray-tracing propagation model is proposed to predict radio loss in indoor environment. Specifically, we opted for the Shooting and Bouncing Rays (SBR) method, together with the Geometrieal Theory of Diffrartion (GTD). Besides the line-of-sight propagation (LOS), we consider that the radio waves may experience reflection, refraction, and diffraction (NLOS). In the Shooting and Bouncing Rays (SBR) method, the transmitter antenna launches a bundle of rays that may or may not reach the receiver. Considering the transmitting antenna as a point, the rays will start to launch from this position and can reach the receiver either directly or after reflections, refractions, diffractions, or even after any combination of the previous effects. To model the environment, a database is built to record geometrical characteristics and information on the constituent materials of the scenario. The database works independently of the simulation program, allowing robustness and flexibility to model other seenarios. Each propagation mechanism is treated separately. In line-of-sight propagation, the main contribution to the received signal comes from the direct ray, while reflected, refracted, and diffracted signal dominate when the line-of-sight is blocked. For this case, the transmitted signal reaches the receiver through more than one path, resulting in a multipath fading. The transmitting channel of a mobile system is simulated by moving either the transmitter or the receiver around the environment. The validity of the method is verified through simulations and measurements. The computed path losses are compared with the measured values at 1.8 GHz ftequency. The results were obtained for the main corridor and room classes adjacent to it. A reasonable agreement is observed. The numerical predictions are also compared with published data at 900 MHz and 2.44 GHz frequencies showing good convergence<br>Este trabalho apresenta um modelo 2,5D de tra?ado de raios para predi??o de propaga??o em ambientes interiores (indoor). Especificamente, optou-se pelo M?todo dos Raios For?ados (SBR) em combina??o com a Teoria Geom?trica da Difra??o (GTD). Considera-se que, al?m de propaga??o em visada direta (LOS), podem ocorrer os mecanismos de reflex?o, refra??o e difra??o (NLOS). No M?todo dos Raios For?ados (SBR), a antena transmissora lan?a um feixe de raios que pode ou n?o alcan?ar o receptor. Considerando a antena transmissora como elemento pontual, os raios s?o lan?ados dessa posi??o, podendo alcan?ar o receptor diretamente ou mediante reflex?es, refra??es, difra??es, ou pela combina??o dessas modalidades de propaga??o. Para o modelamento do ambiente, um banco de dados ? constru?do para armazenar as caracter?sticas geom?tricas e informa??es dos materiais constituintes do cen?rio. O banco de dados funciona independentemente do programa de simula??o, possibilitando robustez ? implementa??o e maior flexibilidade para a representa??o de outros ambientes. Cada mecanismo de propaga??o ? tratado separadamente. Na propaga??o em linha de visada, o raio direto oferece maior contribui??o ao sinal recebido, enquanto o raio refletido, refratado e difratado apresentam maior influ?ncia quando a propaga??o ocorre com obstru??o. Neste caso, o sinal transmitido alcan?a o receptor por diversas trajet?rias, ocorrendo desvanecimento por m?ltiplos percursos. O canal de transmiss?o, no sistema m?vel, ? simulado deslocando-se o transmissor ou o receptor ao longo do ambiente. A valida??o do m?todo ? verificada atrav?s de simula??es e medi??es. As perdas de percurso calculadas s?o comparadas com os valores medidos, na freq??ncia de 1,8 GHz. Os resultados s?o obtidos para ambientes de corredor e salas de aula adjacentes. Uma boa converg?ncia ? observada. Os resultados num?ricos deste trabalho s?o tamb?m comparados com os dispon?veis na literatura especializada, na freq??ncia de 900 MHz e 2,44 GHz, mostrando boa concord?ncia

Dissertação de Mestrado em Matemática, área de Especialização em Estatística, Otimização e Matemática Financeira, apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra<br>Hoje em dia os sistemas de localização por satélite são comumente usados por vários utilizadores. Estes oferecem uma boa solução para os problemas de localização fora de portas, no entanto, no que toca à localização dentro de edifícios ainda deixam a desejar. Os problemas de localização indoor têm sido alvo de investigação, já que não podem ser resolvidos de forma idêntica aos de localização no exterior, uma vez que o sinal dos satélites é fortemente atenuado pela estrutura de edifícios. Este tipo de problemas tem despertado interesse em algumas áreas, como a área da saúde. O tema desta dissertação vem a propósito do trabalho desenvolvido para o estágio proposto pela OnCaring. Pretende-se ao longo deste trabalho estudar métodos como a trilatera ção e a multilateração (capítulo 2) e algumas abordagens a modelos de propagação de sinal com informação sobre a estrutura dos edifícios, que complementam os métodos anteriores (capítulo 3). De seguida encontram-se implementações destes métodos (capítulo 5) e uma análise dos resultados obtidos através dos mesmos (capítulo 6).<br>Nowadays the satellite navigation systems are commonly used by numerous users. They offer a good solution for outdoor localization problems, however, when it comes to localization inside buildings they fall short. Indoor localization problems have been subject of investigation, once they cannot be solved in an identical way to the outdoor ones, because the satellite signal suffers strong attenuation by the buildings' structure. These type of problems have become of interest in certain areas, like the healthcare one. The subject of this dissertation comes in the sequence of the developed work for the internship proposed by OnCaring. In the development of this work it is aimed to study some methods like trilateration and multilateration (chapter 2) and some approaches to signal propagation models considering information about the buildings' structure, which complement the previous methods (chapter 3). Towards the end there are implementations of these methods (chapter 5) and analysis of the results obtained by those (chapter 6).

Yes<br>A modified indoor path loss prediction model is presented, namely Effective Wall Loss Model (EWLM). The modified model is compared to other indoor path loss prediction models using simulation data and real-time measurements. Different operating frequencies and antenna polarizations are considered to verify the observations. In the simulation part, EWLM shows the best performance among other models as it outperforms two times the dual slope model which is the second-best performance. Similar observations were recorded from the experimental results. Linear attenuation and one slope models have similar behaviour, the two models parameters show dependency on operating frequency and antenna polarization.<br>The full-text of this article will be released for public view at the end of the publisher embargo on 3 Oct 2018.

Kriging is proposed as a tool for Wi-Fi signal strength estimation for complex indoor environments. This proposal is based on two studies suggesting that kriging might be suitable for this application. Both of these studies have shortcomings in supporting this proposal, but their results encourage a more in depth investigation into this. Even though kriging is a geostatistical method developed for geographical interpolation, it has been used successfully in a wide range of other applications as well. This further suggests that kriging might be a versatile method to overcome some of the difficul- ties of existing signal strength estimation methods. Two main types of signal strength estimation are deterministic methods and empirical methods. Deterministic methods are generally very complex and requires input parameters that are difficult to obtain. Empirical methods are known to have low accuracy which makes them unreliable for practical use. Three main investigations are presented in order to evaluate the use of kriging for this application. A sampling plan is proposed as part of a generic application protocol for the practical use of kriging for Wi-Fi signal strength. It is concluded that kriging can be conffidently used as an estimation technique for Wi-Fi signal strength in complex indoor environments. Kriging is recommended for practical applications, especially where in- sufficient information is available about a building or where time consuming site surveys are not feasible.<br>MIng (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2015

Thesis (M.S.)--University of Tennessee, Knoxville, 2004.<br>Title from title page screen (viewed Sept. 20, 2004). Thesis advisor: Mostofa K. Howlader. Document formatted into pages (xi, 91 p. : ill. (some col.)). Vita. Includes bibliographical references (p. 83-87).

碩士<br>淡江大學<br>電機工程學系<br>92<br>The implementation of the wireless local area networks (WLANs) inside buildings is growing rapidly. It is important to predict indoor coverage zone. The propagation prediction models that proposed in recent years are paying attention to the effects of propagation and reflection. But in a small room with metallic furniture, diffraction is the main influence on path loss. The propagation prediction model that we propose, the propagation loss and the diffraction loss have been considered in this paper. The simulation and measurement results were done for verifying the feasibility of this model. The mean error between the measurement and the simulation results is within 2dB.

Αντικείμενο της παρούσας διπλωματικής εργασίας είναι η μελέτη των μεθόδων βελτιστοποίησης της ποιότητας των παρεχομένων υπηρεσιών των δικτύων κυτταρικής τηλεφωνίας τρίτης γενιάς σε διαλειπτικό περιβάλλον. Αρχικά γίνεται μια σύντομη ιστορική αναδρομή στην εξέλιξη των συστημάτων κινητών επικοινωνιών και παρουσιάζεται το σημαντικότερο πρότυπο τρίτης γενιάς, το UMTS και τα ιδιαίτερα τεχνικά χαρακτηριστικά του. Στην συνέχεια αναλύεται το LTE το οποίο αποτελεί την τελευταία εξέλιξη των δικτύων τρίτης γενιάς και αναμένεται να αντικαταστήσει το UMTS στο άμεσο μέλλον αποτελώντας στην πραγματικότητα τον πρόδρομο των συστημάτων τέταρτης γενιάς. Στην συνέχεια εστιάζουμε στα διαλειπτικά κανάλια αναλύοντας τα φαινόμενα που παρατηρούνται σε αυτά και τα στατιστικά μοντέλα μέσα από τα οποία περιγράφονται. Παράλληλα διερευνάται η επίδραση των φαινομένων αυτών (θετική ή αρνητική) στο QoS των δικτύων τρίτης γενιάς βάσει των χαρακτηριστικών τους (όπως παρουσιάστηκαν στο κεφάλαιο 1) και οι δυνατότητες για περαιτέρω βελτιστοποίηση κατα τον σχεδιασμό των δικτύων και την σωστή εκμετάλλευση των χαρακτηριστικών του περιβάλλοντος όδευσης. Ιδιαίτερη αναφορά γίνεται στα μοντέλα εσωτερικού χώρου λόγω του μεγάλου φορτίου κίνησης που καλούνται να εξυπηρετήσουν. Στο τελευταίο μέρος παρουσιάζεται η διαδικασία παραμετροποίησης κάποιων σημαντικών μοντέλων και τα αποτελέσματα των εξομοιώσεων που έγιναν στον χώρο του κτηρίου των Ηλεκτρολόγων Μηχανικών.<br>The subject of this diploma thesis is the study of the optimization techniques of the quality of service for third generation cellular telephony networks in fading enviroment. After a short presentation of the evolution of the systems of wireless telecommunications, it is discussed UMTS the most important third generation system which dominated the european market and its technical features. LTE is also introduced, the system which is expected to replace UMTS in the near future while being the predecessor of the fourth generation systems. Then we focus on the fading channels analysing the phenomena wich are related to them and analysing the statistical models that describe them. It is also studied the effect (positive or negative) of these phenomena on the QoS of the third generation networks and the optimization methods which can be applied during the network designing process with special reference to the indoor propagation models because of the big amount of traffic load that they are asked to serve. At the last chapter of the thesis there is a presentation of the parameter setting procedure for some important models and the outcomes of the simulation that took place in the building of Electronic Engineering.

碩士<br>中原大學<br>資訊管理研究所<br>94<br>Wireless local area network widely applies indoors. Its propagation of wireless signals is much different from outdoors. The more obstacles are indoors, the more complicated effects will occur such as multi-path propagation and multi-path reflections. These effects will make magnitude change and quality of wireless signal become harder to predict. When planning a wireless local area network in small region indoors, its access point locations are usually decided by experiences of planners and optimized then again and again by adjustments. Otherwise, it will divide into two ways to plan in wide region. They are site survey and software-aided tools had built-in wireless signal propagation models. It will cost too much labor workforce and time to do site survey, and software-aided tools still have not owned a complete data base to make precise results. The environment of domestic enterprises usually adopts traditional site-survey to plan the infrastructure of wireless local area network more often than not. Though it can achieve the efficiency we expect, it costs too much labor workforce and time. Hence, a wireless propagation model under our research for general indoor environment of enterprises had been established and found the balance between the existing deterministic model and empirical model. We considered the effect of attenuation and reflection to wireless signals propagation indoors and adopted it into our models. Finally, the magnitude distributions of indoor wireless signals we measured are very close to the real environment. In this research, we also mentioned many kinds of decorative material often adopted by enterprises in Taiwan how they affected wireless signal attenuations. Simple ways to calculate and measure maintains precisely predictions in our research. They make designers of wireless infrastructures whom can take our propagation model to arrange every kinds of attenuation parameter caused by indoor obstacles before they start establishing their design. And they will design and plan an appropriate wireless local area network structure in advance.

碩士<br>國立臺灣大學<br>電信工程學研究所<br>92<br>Emerging demand for broadband and high data rates application has stimulated rapid development of wireless industry of nowadays. The 60 GHz band is expected to be a candidate for next-generation WLAN system since a wide range of spectrum has been allocated worldwide. In this thesis, propagation model, channel measurement and system simulation at the 60 GHz band will be studied. For the purpose of simulation of system performance, we have proposed a methodology about indoor wideband channel modeling, which will be extended to 60 GHz band. With practical works of measurement and computer simulation, we have successfully verified the feasibility and correctness of the proposed indoor channel model. In addition, fundamental channel characteristics of 60 GHz band are more understood by going through practical measurement and simulation works. We suggest that directive antennas should be equipped at the receiver end to provide reasonable link quality and system coverage. From the analysis of BER performance and link budget, it reveals that high data rates can be achieved with reasonable system coverage. Besides, human blockage will seriously degrade the system performance and reduce the area coverage.

The well known geometrical scattering channel modeling technique has been suggested to describe the spatial statistical distribution of the received multipath signals at various types of wireless communication environments and for different wireless system applications. This technique is based on the assumption that the scatterers, i.e. objects that give rise to the multipath signals, are randomly distributed within a specified geometry that may include the base station and/or the mobile station. The geometrical scattering channel models can provide convenient and simple statistical functions for some of the important physical quantities of the received multipath fading signals, such as: angle of arrival, time of arrival, angular spread, delay spread and the spatial correlation function. In this thesis, a new three dimensional geometrical scattering channel model has been developed for outdoor and indoor wireless communication environments. The probability density functions of the angle of arrival of the received multipath signals are provided in compact forms. These functions facilitate independent control of the angular spread in both the azimuth and the elevation angles via the model's parameters. To establish the model verification, the developed model has been compared against the results from a site-specific propagation prediction technique in indoor and outdoor wireless communication environments. The developed three dimensional model has been extended to include the temporal statistical distribution of the received multipath signals for uniform and non-uniform distributions of the scatterer. Several of the probability density functions of the angle of arrival and time of arrival of the received multipath signals are provided. The probability density functions of the angle of arrival have been validated by comparing them against the results from real channel measurements data. In addition, the developed three dimensional geometrical scattering channel model has been extended for multiple input multiple output wireless channel modeling applications. A three dimensional spatial correlation function has been developed in terms of some of the physical channel's parameters, such as: displacements and orientation of the employed antenna elements. The developed correlation function has been used to simulate and investigate the performance of wireless multiple input multiple output systems in different scenarios.

Tese de Doutoramento - Programa Doutoral em Engenharia Electrónica e Computadores<br>Positioning technologies are ubiquitous nowadays. From the implementation of the global positioning system (GPS) until now, its evolution, acceptance and spread has been unanimous, due to the underlying advantages the system brings. Currently, these systems are present in many different scenarios, from the home to the movie theatre, at work, during a walk in the park. Many applications provide useful information, based on the current position of the user, in order to provide results of interest. Positioning systems can be implemented in a wide range of contexts: in hospitals to locate equipment and guide patients to the necessary resources, or in public spaces like museums, to guide tourists during visits. They can also be used in a gymnasium to point the user to his next workout machine and, simultaneously, gather information regarding his fitness plan. In a congress or conference, the positioning system can be used to provide information to its participants about the on-going presentations. Devices can also be monitored to prevent thefts. Privacy and security issues are also important in positioning systems. A user might not want to be localized or its location to be known, permanently or during a time interval, in different locations. This information is therefore sensitive to the user and influences directly the acceptance of the system itself. Concerning outdoor systems, GPS is in fact the system of reference. However, this system cannot be used in indoor environment, due to the high attenuation of the satellite signals from non-line-of-sight conditions. Another issue related to GPS is the power consumption. The integration of these devices with wireless sensor networks becomes prohibitive, due to the low power consumption profile associated with devices in this type of networks. As such, this work proposes an indoor positioning system for wireless sensor networks, having in consideration the low energy consumption and low computational capacity profile. The proposed indoor positioning system is composed of two modules: the received signal strength positioning module and the stride and heading positioning module. For the first module, an experimental performance comparison between several received signal strength based algorithms was conducted in order to assess its performance in a predefined indoor environment. Modifications to the algorithm with higher performance were implemented and evaluated, by introducing a model of the effect of the human body in the received signal strength. In the case of the second module, a stride and heading system was proposed, which comprises two subsystems: the stride detection and stride length estimation system to detect strides and infer the travelled distance, and an attitude and heading reference system to provide the full three-dimensional orientation stride-by-stride. The stride detection enabled the identification of the gait cycle and detected strides with an error percentage between 0% and 0.9%. For the stride length estimation two methods were proposed, a simplified method, and an improved method with higher computational requirements than the former. The simplified method estimated the total distance with an error between 6.7% and 7.7% of total travelled distance. The improved method achieved an error between 1.2% and 3.7%. Both the stride detection and the improved stride length estimation methods were compared to other methods in the literature with favourable results. For the second subsystem, this work proposed a quaternion-based complementary filter. A generic formulation allows a simple parameterization of the filter, according to the amount of external influences (accelerations and magnetic interferences) that are expected, depending on the location that the device is to be attached on the human body. The generic formulation enables the inclusion/exclusion of components, thus allowing design choices according to the needs of applications in wireless sensor networks. The proposed method was compared to two other existing solutions in terms of robustness to interferences and execution time, also presenting a favourable outcome.<br>Os sistemas de posicionamento fazem parte do quotidiano. Desde a implementação do sistema GPS (Global Positioning System) até aos dias que correm, a evolução, aceitação e disseminação destes sistemas foi unânime, derivada das vantagens subjacentes da sua utilização. Hoje em dia, eles estão presentes nos mais variados cenários, desde o lar até́ à sala de cinema, no trabalho, num passeio ao ar livre. São várias as aplicações que nos fornecem informação útil, usando como base a descrição da posição atual, de modo a produzir resultados de maior interesse para os utilizadores. Os sistemas de posicionamento podem ser implementados nos mais variados contextos, como por exemplo: nos hospitais, para localizar equipamento e guiar os pacientes aos recursos necessários, ou nas grandes superfícies públicas, como por exemplo museus, para guiar os turistas durante as visitas. Podem ser igualmente utilizados num ginásio para indicar ao utilizador qual a máquina para onde se deve dirigir durante o seu treino e, simultaneamente, obter informação acerca desta mesma máquina. Num congresso ou conferência, o sistema de localização pode ser utilizado para fornecer informação aos seus participantes sobre as apresentações que estão a decorrer no momento. Os dispositivos também podem ser monitorizados para prevenir roubos. Existem também questões de privacidade e segurança associados aos sistemas de posicionamento. Um utilizador poderá não desejar ser localizado ou que a sua localização seja conhecida, permanentemente ou num determinado intervalo de tempo, num ou em vários locais. Esta informação é por isso sensível ao utilizador e influencia diretamente a aceitação do próprio sistema. No que diz respeito aos sistemas utilizados no exterior, o GPS (ou posicionamento por satélite) é de facto o sistema mais utilizado. No entanto, em ambiente interior este sistema não pode ser usado, por causa da grande atenuação dos sinais provenientes dos satélites devido à falta de linha de vista. Um outro problema associado ao recetor GPS está relacionado com as suas características elétricas, nomeadamente os consumos energéticos. A integração destes dispositivos nas redes de sensores sem fios torna-se proibitiva, devido ao perfil de baixo consumo associado a estas redes. Este trabalho propõe um sistema de posicionamento para redes de sensores sem fio em ambiente interior, tendo em conta o perfil de baixo consumo de potência e baixa capacidade de processamento. O sistema proposto é constituído por dois módulos: o modulo de posicionamento por potência de sinal recebido e o módulo de navegação inercial pedestre. Para o primeiro módulo foi feita uma comparação experimental entre vários algoritmos que utilizam a potência do sinal recebido, de modo a avaliar a sua utilização num ambiente interior pré-definido. Ao algoritmo com melhor prestação foram implementadas e testadas modificações, utilizando um modelo do efeito do corpo na potência do sinal recebido. Para o segundo módulo foi proposto um sistema de navegação inercial pedestre. Este sistema é composto por dois subsistemas: o subsistema de deteção de passos e estimação de distância percorrida; e o subsistema de orientação que fornece a direção do movimento do utilizador, passo a passo. O sistema de deteção de passos proposto permite a identificação das fases da marcha, detetando passos com um erro entre 0% e 0.9%. Para o sistema de estimação da distância foram propostos dois métodos: um método simplificado de baixa complexidade e um método melhorado, mas com maiores requisitos computacionais quando comparado com o primeiro. O método simplificado estima a distância total com erros entre 6.7% e 7.7% da distância percorrida. O método melhorado por sua vez alcança erros entre 1.2% e 3.7%. Ambos os sistemas foram comparados com outros sistemas da literatura apresentando resultados favoráveis. Para o sistema de orientação, este trabalho propõe um filtro complementar baseado em quaterniões. É utilizada uma formulação genérica que permite uma parametrização simples do filtro, de acordo com as influências externas (acelerações e interferências magnéticas) que são expectáveis, dependendo da localização onde se pretende colocar o dispositivo no corpo humano. O algoritmo desenvolvido permite a inclusão/exclusão de componentes, permitindo por isso liberdade de escolha para melhor satisfazer as necessidades das aplicações em redes de sensores sem fios. O método proposto foi comparado com outras soluções em termos de robustez a interferências e tempo de execução, apresentando também resultados positivos.