The aim of this term project was to analyze wireless indoor localization. It contains analysis of some wireless localization techniques such as Time of Arrival or Time Difference of Arrival. The paper also describes the system of SEWIO Company. Main part of the master’s thesis is description, design and implementation of the Kalman filter. The Kalman filter is used to improve two-dimensional positional data and synchronization of anchors (devices for finding a position of an object in SEWIO system). There are described a few system models for the Kalman filter.

No description available.

[pt] Este trabalho lida com o problema de radiolocalização de terminais em um ambiente de comunicações móveis celulares. Desenvolve-se novas alternativas para a estimação da posição, admitindo-se que as medidas de tempo de chegada (ToA) obtidas no enlace-rádio estão corrompidas por ruído aditivo e apresentam erro médio positivo durante períodos aleatórios, devido à ausência de linha de visada (NLOS) entre terminal e estações radio-bases. Em uma das alternativas desenvolve-se um estimador assintoticamente eficiente do erro de NLOS, sob o critério de mínimos quadrados ponderados (WLS). Para esta estimativa, admite- se o conhecimento a priori do espalhamento temporal do canal, e que o perfil de potência do sinal pode ser calculado por uma média temporal de medidas independentes em um receptor RAKE. O esquema de localização apresentado incorpora também um teste de hipóteses desenvolvido sob o critério de Neyman-Pearson, para detectar, a cada instante de tempo, a ocorrência de transições entre os estados LOS/NLOS do canal. Em outra contribuição do trabalho, as coordenadas do terminal são estimadas recursivamente utilizando-se algoritmos bayesianos, com a dimensão do espaço de estados aumentada para incluir o efeito do erro de NLOS sobre as medidas de ToA. Resultados de simulação obtidos sob diferentes cenários comprovam a eficiência dos esquemas de estimação aqui desenvolvidos, quando comparados à única solução de que se tem conhecimento na literatura. Apresenta-se ainda nesta tese uma análise para o problema de ambigüidade em métodos hiperbólicos de localização, cujo objetivo é identificar a região do plano em que este método fornece duas soluções fisicamente admissíveis. A área desta região é comparada com a área total de triangulação. / [en] This work addresses the radiolocation problem of a moving terminal in a cellular mobile communications environment. New alternatives are developed for position estimation, assuming that the Time of Arrival (ToA) measurements obtained from radio link are corrupted by additive noise and have positive mean error during random periods of time due to the non-line of sight (NLOS) propagation condition between the terminal and base stations. In one of the proposals, an asymptotically efficient WLS estimator of the NLOS error is developed under the Weighted Least Squares criterion. It is assumed that the channel temporal scattering model is known and the mean power delay profile can be evaluated by time averaging independent measurements from a RAKE receiver. The location estimation scheme also includes a hypothesis testing based on Neyman- Pearson approach to detect at each instant of time the LOS/NLOS states transitions. In another contribution, the terminal coordinates are recursively estimated using bayesian algorithms, with the state-space dimension augmented to include the NLOS error effect over ToA measurements. Simulation results obtained under different scenarios show the effectiveness of the estimation schemes developed here when compared to the only alternative known from the literature. An analysis concerning the ambiguity problem in hyperbolic location methods is also presented, aiming to determine the regions where this method gives two physically admissible solutions, and compare them to the total trilateration area.

In this paper we suggest a lightning detection system capable of warning a local populous of incoming lightning weather using a combination of the AS3935 sensor and the one-board-computer Raspberry Pi, in an attempt to design a product that is cheap, mobile and easy to use. The product is composed of a sensor net that registers and reports lightnings on a webserver. The server is reachable as a normal website based on the LAMP method. The project reached a stadium which should satisfy a “proof of concept”, however, the product is far from complete, as it lacks the necessary algorithms needed for proper data computation. The current system only uses Raspberry pi, but it is theoretically possible to introduce other hardware to the system, but the current developed product does not support such functionality. / I den här rapporten föreslår vi ett blixtlokaliseringssystem kapabelt att varna lokal befolkningen om inkommande blixtväder med hjälp av en kombination av sensorn AS3935 och enchipsdatorn Raspberry Pi, i ett försök att skapa en produkt som är billig, mobil och användarvänlig. Systemet består av ett nät av sensorer som registrerar och rapporterar blixtaktivitet på en webbserver. Servern är nåbar som en vanlig hemsida som är byggd enligt LAMP metoden. Projektet har nått ett stadium som borde uppnå kraven för ett ”bevis av ett koncept”, men produkten är långt ifrån färdig, då den saknar de nödvändiga algoritmerna som krävs för ordentlig databehandling. Det nuvarande systemet använder sig enbart av Rasberry Pi:s, men i teorin vore det fullt möjligt att introducera ny hårdvara i nätet, men den nuvarande produkten stöder inte sådan funktionalitet.

Recently, there are great interests in the location-based applications and the location-awareness of mobile wireless systems in indoor areas, which require accurate location estimation in indoor environments. The traditional geolocation systems such as the GPS are not designed for indoor applications, and cannot provide accurate location estimation in indoor environments. Therefore, there is a need for new location finding techniques and systems for indoor geolocation applications. In this thesis, a wide variety of technical aspects and challenging issues involved in the design and performance evaluation of indoor geolocation systems are presented first. Then the TOA estimation techniques are studied in details for use in indoor multipath channels, including the maximum-likelihood technique, the MUSIC super-resolution technique, and diversity techniques as well as various issues involved in the practical implementation. It is shown that due to the complexity of indoor radio propagation channels, dramatically large estimation errors may occur with the traditional techniques, and the super-resolution techniques can significantly improve the performance of the TOA estimation in indoor environments. Also, diversity techniques, especially the frequency-diversity with the CMDCS, can further improve the performance of the super-resolution techniques.

Submitted by camilla martins (camillasmmartins@gmail.com) on 2017-03-24T17:51:47Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EstimacaoLocalIncidencia.pdf: 4971817 bytes, checksum: 4744fadf79bcf26c484dcae5dfb89992 (MD5) / Approved for entry into archive by Edisangela Bastos (edisangela@ufpa.br) on 2017-03-27T14:35:40Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EstimacaoLocalIncidencia.pdf: 4971817 bytes, checksum: 4744fadf79bcf26c484dcae5dfb89992 (MD5) / Made available in DSpace on 2017-03-27T14:35:40Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EstimacaoLocalIncidencia.pdf: 4971817 bytes, checksum: 4744fadf79bcf26c484dcae5dfb89992 (MD5) Previous issue date: 2016-03-22 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / Ao longo dos anos, os relâmpagos constituíram o ponto central das pesquisas de diversas comunidades científicas e tecnológicas em todo mundo, sem dúvida pela sua natureza agressiva e devastadora, mas principalmente pelos prejuízos causados no setor elétrico, logo é necessário esclarecer, o que é e para que serve um Sistema de Localização de Tempestades (SLT). Este trabalho propõe demonstrar o funcionamento de um algoritmo utilizado em SLT que serve para localizar, em termos geográficos, descargas atmosféricas, utilizando os tempos de chegada dos sinais eletromagnéticos nos elementos sensores. Para elaboração deste trabalho foi utilizado o formato de dados gerados por sensores LPATS IV pertencentes a (REDE DO SIPAM) e estes dados foram gerados de forma artificial para utilização no algoritmo. Esta localização será baseada em uma sequência finitas de regras que utilizará como ferramenta, a interseção de futuras hipérboles, resultantes da diferença dos tempos de chegada em cada sensor. O algoritmo é capaz de identificar o local de incidência da descarga atmosférica utilizando um simples sistema de três sensores. Cada par de sensores define duas hipérboles, em virtude de sua parte positiva e negativa formando duas interseções. Para análise do resultado é considerado o ponto de cruzamento mais próximo ao sensor que identificou a perturbação com menor tempo. Um estudo sobre a eletricidade atmosférica, tipos de raios, emissão de ondas eletromagnéticas durante tempestades, tipos de sensores eletromagnéticos e redes de detecção de raios deram subsídio para o projeto do algoritmo desenvolvido. / Over the years, lightning were the central point of researches in various scientific communities around the world, no doubt for its aggressive and devastating nature, but mostly for damage caused in the electricity sector, so it is necessary to clarify what is and what it is for a Lightning Location System (LLS). This work proposes to demonstrate the operation of the algorithm utilized in LLS that is used to locate in geographical terms, lightning, using the arrival times of electromagnetic signals in the sensors. In order to prepare this paper it was used the data format generated by LPATS IV sensors belonging to Amazon Protection System (SIPAM). These data were generated in an artificial way for use in the algorithm tests. The lightning location will be based on a finite sequence rules that use the intersection of hyperbolas, resulting from the difference of arrival times at each sensor. The algorithm is able to identify the lightning location incidence using a system with three sensors. Each pair of sensors defines two hyperbole forming a total of six, because each hyperbole has a bright side and a negative side, so there will be two intersections of three hyperboles. For analysis of the results is considered the nearest crossing point to the sensor that identified the electromagnetic disturbance faster. Studies about atmospheric electricity, lightning types, electromagnetic radiation during storms, types of electromagnetic sensors and lightning detection networks have given the knowledge to develop the algorithm.

Cette thèse s'inscrit dans le projet de communication à proximité aux départements Electronique et Physique et Communications, Images et Traitement de l'Information de l'Institut Télécom Sud Paris. Le projet comporte la mise au point d'un récepteur basé sur une méthode de détection pseudo-cohérente des signaux Ultra Large Bande à double impulsion (TR-UWB), méthode désignée par Time Delayed Sampling and Correlation (TDSC). La première partie de ce document comporte la réalisation d'une plate-forme modulaire de communication UWB basée sur le système de détection TDSC. Cette plate-forme comporte une puce CMOS 0.35μm conçue précédemment au laboratoire EPH. Elle offre la possibilité d'enregistrer des signaux TR-UWB réels et de réaliser des tests de fonctionnement. La deuxième partie est une étude approfondie du récepteur utilisant la méthode TDSC. La détection des signaux UWB et la procédure de synchronisation sont évalués en utilisant les signaux réels acquis à partir de la plate-forme. Un ensemble de tests ont été menés avec des signaux en bande de base et des signaux transposés en fréquence, dans les deux cas en transmission sur câble puis par radio. Les résultats ont permis de valider la détection et le principe de la synchronisation. La troisième partie est une proposition d'estimation de la distance entre deux dispositifs d'un réseau radio UWB utilisant un récepteur TDSC, pour une localisation en intérieur. L'étude fait la synthèse de plusieurs propositions et expérimentations et conduit à la définition des meilleurs critères pour une mesure du temps d'arrivée (TOA) et son implémentation pratique sur un récepteur TDSC

La localisation active et passive par un réseau de capteurs distribués est un problème rencontré dans différents domaines d’application. En localisation active, telle que la localisation par radar MIMO (Multiple Input Multiple Output), les émetteurs transmettent des signaux qui sont réfléchis par les cibles visées, puis captés par les antennes réceptrices, alors qu’en localisation passive, les capteurs reçoivent des signaux transmis par les cibles elles-mêmes. L’objectif de cette thèse est d’étudier différentes techniques d’optimisation pour la localisation active et passive de haute précision. Dans la première partie de la thèse, on s’intéresse à la localisation active, où de multiples émetteurs illuminent les cibles depuis différentes directions. Les signaux peuvent être émis avec des puissances ou des largeurs de bande différentes. Ces différentes ressources, par nature en général fortement limitées, sont souvent, par défaut, réparties de façon uniforme entre les différents émetteurs. Or, la précision de la localisation dépend de la position des émetteurs, ainsi que des paramètres (les gains notamment) des différents canaux existant entre émetteurs, cibles, et capteurs. En utilisant comme critère d’optimisation la borne de Cramér-Rao sur la précision de la localisation de cibles multiples, nous proposons une méthode fournissant des solutions approchées aux problèmes d’allocation optimale de puissances seules, de largeurs de bande seules, ou au problème d’allocation conjointe de puissances et de largeurs de bande. Ces solutions sont obtenues en minimisant une suite de problèmes convexes. La qualité de ces solutions approchées est évaluée au travers de nombreuses simulations numériques, mais également par la comparaison avec une borne inférieure définie comme la solution d’un problème d’optimisation avec contraintes relaxées, cette borne pouvant être calculée de façon exacte (numériquement). Cette comparaison permet de constater la proximité de la solution approchée fournie par l’algorithme proposé par rapport à la solution théorique. D’autre part, les simulations ont montré que l’allocation de bande joue un rôle plus important dans les performances de localisation que l’allocation de puissance. Dans la seconde partie de la thèse, on considère le cas de la localisation passive de sources multiples dans un environnement multi-trajet. Ce problème se rencontre notamment dans le cadre de la géolocalisation indoor ou outdoor. Dans ce cas de figure, les approches généralement proposées dans la littérature sont basées sur une méthode ad-hoc de réduction d’interférence couplée à une localisation indirecte obtenue par une estimation de paramètres comme les temps d’arrivée des signaux ou les différences de temps d’arrivée, ou la puissance des signaux reçus. Cependant, les performances de ces approches sont limitées, notamment par le fait que la localisation indirecte d’une cible donnée ne prend pas en compte le fait que les signaux reçus par les différents capteurs émanent d’une seule et même source. Dans cette thèse, nous proposons une modélisation parcimonieuse des signaux reçus. Cette modélisation nous permet, en supposant les formes d’onde connues mais les canaux multi-trajets totalement inconnus, de développer une méthode de localisation directe de l’ensemble des cibles. Cette approche exploite certaines propriétés des canaux, qui permettent de séparer les trajets directs des trajets indirects. Un algorithme d’optimisation conique de second ordre est développé afin d’obtenir une décomposition dite atomique optimale, qui permet d’obtenir une localisation de très bonne précision dans des conditions de propagation difficiles, présentant un phénomène de multi-trajet important et/ou une absence de trajets directs. / Active and passive localization employing widely distributed sensors is a problem of interest in various fields. In active localization, such as in MIMO radar, transmitters emit signals that are reflected by the targets and collected by the receive sensors, whereas, in passive localization the sensors collect the signals emitted by the sources themselves. This dissertation studies optimization methods for high precision active and passive localization. In the case of active localization, multiple transmit elements illuminate the targets from different directions. The signals emitted by the transmitters may differ in power and bandwidth. Such resources are often limited and distributed uniformly among the transmitters. However, previous studies based on the well known Crámer-Rao lower bound have shown that the localization accuracy depends on the locations of the transmitters as well as the individual channel gains between different transmitters, targets and receivers. Thus, it is natural to ask whether localization accuracy may be improved by judiciously allocating such limited resources among the transmitters. Using the Crámer-Rao lower bound for target localization of multiple targets as a figure of merit, approximate solutions are proposed to the problems of optimal power, optimal bandwidth and optimal joint power and bandwidth allocation. These solutions are computed by minimizing a sequence of convex problems. The quality of these solutions is assessed through extensive numerical simulations and with the help of a lower-bound that certifies their optimality. Simulation results reveal that bandwidth allocation policies have a stronger impact on performance than power. Passive localization of radio frequency sources over multipath channels is a difficult problem arising in applications such as outdoor or indoor geolocation. Common approaches that combine ad-hoc methods for multipath mitigation with indirect localization relying on intermediary parameters such as time-of-arrivals, time difference of arrivals or received signal strengths, are unsatisfactory. This dissertation models the localization of known waveforms over unknown multipath channels in a sparse framework, and develops a direct approach in which multiple sources are localized jointly, directly from observations obtained at distributed sources. The proposed approach exploits channel properties that enable to distinguish line-of-sight (LOS) from non-LOS signal paths. Theoretical guarantees are established for correct recovery of the sources’ locations by atomic norm minimization. A second-order-cone-based algorithm is developed to produce the optimal atomic decomposition, and it is shown to produce high accuracy location estimates over complex scenes, in which sources are subject to diverse multipath conditions, including lack of LOS.

The first part of this thesis develops methods for UWB communication. To meet the stringent regulatory body constraints, the physical layer signaling technique of the UWB transceiver should be optimally designed. We propose two signaling schemes which are variants of pulse position modulation (PPM) signaling for impulse radio (IR) UWB communication. We also discuss the detectors for the signaling schemes and evaluate the performance of these detectors.  IR-UWB can be used for precise range measurements as it provides a very high time resolution. This enables accurate time of arrival (TOA) estimations from which precise range values can be derived. We propose methods which use range information to arrive at optimal schedules for an all-to-all broadcast problem. Results indicate that throughput can be increased on average by three to ten times for typical network configurations compared to the traditional methods. Next, we discuss hypothesis testing in the context of UWB transceivers. We show that, when multiple detector outputs from a hardware platform are available, fusing the results from them can yield better performance in hypothesis testing than relying on a single detector output. In the second part of this thesis, the emphasis is placed on localization and joint estimation of location and communication parameters. Here, we focus on estimating the TOA of the signal. The wide bandwidth of the UWB signal requires high speed analog to digital converts (ADC) which makes the cost of the digital transceivers prohibitively high. To address this problem, we take two different strategies. In the first approach, we propose a multichannel receiver with each channel having a low-cost energy detector operating at a sub-Nyquist rate. In the second approach, we consider a compressive sampling based technique. Here, we propose a new acquisition front end, using which the sampling rate of the ADC can be significantly reduced. We extended the idea of compressive sampling based TOA estimation towards joint estimation of TOA and PPM symbols. Here, two signaling methods along with the algorithms are proposed based on the dynamicity of the target. They provide similar performance to the ML based estimation, however with a significant savings in the ADC resources. / <p>QC 20161205</p>

No description available.