9 research outputs found

    A Review of pedestrian indoor positioning systems for mass market applications

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    In the last decade, the interest in Indoor Location Based Services (ILBS) has increased stimulating the development of Indoor Positioning Systems (IPS). In particular, ILBS look for positioning systems that can be applied anywhere in the world for millions of users, that is, there is a need for developing IPS for mass market applications. Those systems must provide accurate position estimations with minimum infrastructure cost and easy scalability to different environments. This survey overviews the current state of the art of IPSs and classifies them in terms of the infrastructure and methodology employed. Finally, each group is reviewed analysing its advantages and disadvantages and its applicability to mass market applications

    A reduced complexity approach to IAA beamforming for efficient DOA estimation of coherent sources

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    Altres ajuts : Chair of Knowledge and Technology Transfer Parc de Recerca UAB-SantanderWe address the 2D direction-of-arrival (DOA) estimation problem in scenarios with coherent sources. More specifically, we adopt beamforming solutions based on the iterative adaptive approach (IAA) recently proposed in the literature. The motivation of such adoption mainly comes from the excellent behavior these beamformers provide in scenarios with coherent sources. Nonetheless, these strategies suffer from a prohibitive computational complexity, especially in 2D scenarios. In order to alleviate the, we propose two reduced-complexity (RC) versions of the IAA and IAA based on maximum likelihood (IAA-ML) algorithms. The proposed beamformers are referred to as IAA-RC and IAA-ML-RC and provide similar results to those obtained with their original counterparts. Computational complexity, however, is further reduced. Numerical results presented in the paper show that the computational burden can be decreased by a 52 with our proposed solutions in the considered scenarios

    Cooperative strategies for imperfect CSI scenarios based on distributed Alamouti

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    Les comunicacions cooperatives estan guanyant un gran inter猫s en les comunicacions modernes degut a que permeten millorar la transmissi贸 d始informaci贸 entre un emissor i un receptor utilitzant una s猫rie de terminals situats entre ells. Aquest projecte 茅s un estudi complet del sistemes cooperatius, analitzant el seu rendiment i comparant l始煤s d始un sol d始aquests terminals amb l始煤s del codi Alamouti, que utilitza dos terminals. Primer hi ha una introducci贸 als sistemes cooperatius i a la teoria de la informaci贸. Despr茅s hem estudiat un sistema cooperatiu amb la teoria de la informaci贸 com a base, en termes de probabilitat de fallada del sistema, i posteriorment l始hem adaptat a un sistema cooperatiu real utilitzant una modulaci贸 QPSK, estudiant la seva probabilitat d始error de paquet. Finalment es proposen diversos protocols que permeten millorar el rendiment del sistema cooperatiu estudiat.Las comunicaciones cooperativas est谩n ganando mucho inter茅s en las comunicaciones modernas debido a que permiten mejorar la transmisi贸n de informaci贸n entre un emisor y un receptor usando una serie de terminales intermedios. Este proyecto es un estudio completo de los sistemas cooperativos, analizando su rendimiento y comparando el uso de uno solo de estos terminales con el uso del c贸digo Alamouti, el cual usa dos terminales. Primero hay una introducci贸n a los sistemas cooperativos y a la teor铆a de la informaci贸n. Despu茅s hemos estudiado un sistema cooperativo con la teor铆a de la informaci贸n como base, en t茅rminos de probabilidad de fallo del sistema, y posteriormente lo hemos adaptado a un sistema cooperativo real usando una modulaci贸n QPSK, estudiando su probabilidad de error de paquete. Finalmente se proponen varios protocolos que permiten mejorar el rendimiento del sistema cooperativo estudiado.Cooperative communications are gaining much interest in modern communications because they allow to improve the information transmission between a source and a destination using various intermediate terminals. This project is a complete study of cooperative systems, analyzing its performance and comparing the use of a single terminal with the use of the Alamouti code, which uses two terminals. First, there is an introduction to cooperative systems and to information theory. Then we have studied a cooperative system using the information theory, in terms of outage probability, and subsequently we have adapted it to a real cooperative system using a QPSK modulation, studying its packet error probability. Finally several protocols are proposed to improve the performance of the studied cooperative system

    Wireless sensor networks in the future internet of things: density, mobility, heterogeneity and integration

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    Las redes de sensores inal谩mbricos est谩n destinadas a revolucionar nuestra manera de vivir, trabajar y relacionarnos con el entorno. Aunque este tipo de redes ha estado en el foco de la investigaci贸n cient铆fica durante la 煤ltima d茅cada, su rendimiento en implementaciones pr谩cticas est谩 todav铆a muy por detr谩s de los resultados te贸ricos. Esto es en gran parte debido a los problemas pr谩cticos que aparecen en entornos reales. Como resultado, su uso est谩 generalmente limitado a aplicaciones simples de monitorizaci贸n del entorno. El objetivo de esta tesis es reducir el margen entre el potencial te贸rico y real de las redes de sensores inal谩mbricos y de esta manera incrementar su integraci贸n dentro de la sociedad. En concreto, la tesis se centra en los siguientes cuatro obst谩culos: alta densidad de nodos, movilidad de nodos, tr谩fico heterog茅neo e integraci贸n en el internet de las cosas. Primero, el objetivo es el de reducir las interferencias en despliegues de alta densidad de nodos. Para ello se propone un esquema pr谩ctico para realizar el enrutado, el control de potencia y la selecci贸n de canal, basado en el protocolo RPL (Routing Protocol for Low-Power and Lossy Networks). Esta soluci贸n permite reducir las colisiones entre paquetes y adem谩s mejorar el consumo energ茅tico de este tipo de redes. Segundo, se pretende mejorar la baja fiabilidad y robustez de las redes de sensores inal谩mbricos con nodos m贸viles. Con este objetivo se presenta un m茅todo que combina RPL con un sistema de enrutado que considera la posici贸n de los nodos basado en el filtro de Kalman. 脡ste combina la eficiencia y fiabilidad de RPL permitiendo adem谩s manejar nodos m贸viles. Tercero, se estudian maneras de proporcionar la calidad de servicio necesaria a las redes de sensores con tr谩fico heterog茅neo. Para ello se propone una estrategia multi 谩rbol basada en la construcci贸n de m煤ltiples instancias RPL. 脡sta construye diferentes topolog铆as virtuales para cada funci贸n objetivo, y de esta manera es posible atender los requisitos de cada flujo de tr谩fico de manera independiente. Finalmente, se estudia la manera de integrar las redes de sensores inal谩mbricos dentro de la nube y el internet de las cosas. Con este objetivo se propone una formulaci贸n para coordinar la utilizaci贸n de los recursos de la red de manera conjunta usando estrategias de virtualizaci贸n y computaci贸n m贸vil en la nube. Esto permite reducir el consumo energ茅tico de la red, teniendo en cuenta las capacidades y limitaciones de cada nodo, satisfaciendo tanto los requisitos de los diferentes servicios como los de los usuarios.Wireless sensor networks (WSNs) are expected to revolutionize the way we live, work, and interact with the physical environment. Although WSNs have been in the spotlight of the research community for the last decade, their performance in practical implementations is still far behind the theoretical results. This is mainly due to the practical issues that arise in real-life scenarios. As a result, WSNs are generally limited to simple environmental sensing applications. The aim of this thesis is to reduce the gap between the theoretical and real potential of WSNs, and therefore increase their integration in society. In particular, this thesis focuses on the following four practical obstacles: high node density, node mobility, traffic heterogeneity and integration with the future Internet of Things (IoT). First, we deal with the interference problem in high density sensor deployments. We address this issue proposing a pragmatic joint routing, transmission power control and channel allocation approach, built upon the well-known RPL (Routing Protocol for Low-Power and Lossy Networks). This reduces the average packet collisions and the energy consumption of WSNs. Second, we address the low communication reliability and robustness in WSNs with mobile nodes. In particular, we propose a solution that combines RPL with a position-based routing approach based on Kalman filtering. This provides the efficiency and reliability of RPL, and also includes mobility support for non-static nodes. Third, we study the problem of QoS (Quality of Service) provisioning in WSNs managing heterogeneous traffic. With this in mind, we propose a multi-tree approach based on the construction of multiple RPL Instances. This constructs multiple virtual topologies to address the particular requirements of each traffic flow individually. Finally, we focus on the efficient integration of wireless sensors with Cloud-based IoT platforms. In particular, we propose a formulation to orchestrate the resource utilization of the whole network, taking advantage of the recent advances in virtualization and mobile cloud computing. This optimizes the overall consumption, considering the capabilities and limitations of each node, while satisfying the service requirements and the individual users' demands

    Cooperative strategies for imperfect CSI scenarios based on distributed Alamouti

    No full text
    Les comunicacions cooperatives estan guanyant un gran inter猫s en les comunicacions modernes degut a que permeten millorar la transmissi贸 d始informaci贸 entre un emissor i un receptor utilitzant una s猫rie de terminals situats entre ells. Aquest projecte 茅s un estudi complet del sistemes cooperatius, analitzant el seu rendiment i comparant l始煤s d始un sol d始aquests terminals amb l始煤s del codi Alamouti, que utilitza dos terminals. Primer hi ha una introducci贸 als sistemes cooperatius i a la teoria de la informaci贸. Despr茅s hem estudiat un sistema cooperatiu amb la teoria de la informaci贸 com a base, en termes de probabilitat de fallada del sistema, i posteriorment l始hem adaptat a un sistema cooperatiu real utilitzant una modulaci贸 QPSK, estudiant la seva probabilitat d始error de paquet. Finalment es proposen diversos protocols que permeten millorar el rendiment del sistema cooperatiu estudiat.Las comunicaciones cooperativas est谩n ganando mucho inter茅s en las comunicaciones modernas debido a que permiten mejorar la transmisi贸n de informaci贸n entre un emisor y un receptor usando una serie de terminales intermedios. Este proyecto es un estudio completo de los sistemas cooperativos, analizando su rendimiento y comparando el uso de uno solo de estos terminales con el uso del c贸digo Alamouti, el cual usa dos terminales. Primero hay una introducci贸n a los sistemas cooperativos y a la teor铆a de la informaci贸n. Despu茅s hemos estudiado un sistema cooperativo con la teor铆a de la informaci贸n como base, en t茅rminos de probabilidad de fallo del sistema, y posteriormente lo hemos adaptado a un sistema cooperativo real usando una modulaci贸n QPSK, estudiando su probabilidad de error de paquete. Finalmente se proponen varios protocolos que permiten mejorar el rendimiento del sistema cooperativo estudiado.Cooperative communications are gaining much interest in modern communications because they allow to improve the information transmission between a source and a destination using various intermediate terminals. This project is a complete study of cooperative systems, analyzing its performance and comparing the use of a single terminal with the use of the Alamouti code, which uses two terminals. First, there is an introduction to cooperative systems and to information theory. Then we have studied a cooperative system using the information theory, in terms of outage probability, and subsequently we have adapted it to a real cooperative system using a QPSK modulation, studying its packet error probability. Finally several protocols are proposed to improve the performance of the studied cooperative system

    A Review of pedestrian indoor positioning systems for mass market applications

    No full text
    In the last decade, the interest in Indoor Location Based Services (ILBS) has increased stimulating the development of Indoor Positioning Systems (IPS). In particular, ILBS look for positioning systems that can be applied anywhere in the world for millions of users, that is, there is a need for developing IPS for mass market applications. Those systems must provide accurate position estimations with minimum infrastructure cost and easy scalability to different environments. This survey overviews the current state of the art of IPSs and classifies them in terms of the infrastructure and methodology employed. Finally, each group is reviewed analysing its advantages and disadvantages and its applicability to mass market applications

    Wireless sensor networks in the future internet of things : density, mobility, heterogeneity and integration /

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    Premi Extraordinari de Doctorat concedit pels programes de doctorat de la UAB per curs acad猫mic 2017-2018Las redes de sensores inal谩mbricos est谩n destinadas a revolucionar nuestra manera de vivir, trabajar y relacionarnos con el entorno. Aunque este tipo de redes ha estado en el foco de la investigaci贸n cient铆fica durante la 煤ltima d茅cada, su rendimiento en implementaciones pr谩cticas est谩 todav铆a muy por detr谩s de los resultados te贸ricos. Esto es en gran parte debido a los problemas pr谩cticos que aparecen en entornos reales. Como resultado, su uso est谩 generalmente limitado a aplicaciones simples de monitorizaci贸n del entorno. El objetivo de esta tesis es reducir el margen entre el potencial te贸rico y real de las redes de sensores inal谩mbricos y de esta manera incrementar su integraci贸n dentro de la sociedad. En concreto, la tesis se centra en los siguientes cuatro obst谩culos: alta densidad de nodos, movilidad de nodos, tr谩fico heterog茅neo e integraci贸n en el internet de las cosas. Primero, el objetivo es el de reducir las interferencias en despliegues de alta densidad de nodos. Para ello se propone un esquema pr谩ctico para realizar el enrutado, el control de potencia y la selecci贸n de canal, basado en el protocolo RPL (Routing Protocol for Low-Power and Lossy Networks). Esta soluci贸n permite reducir las colisiones entre paquetes y adem谩s mejorar el consumo energ茅tico de este tipo de redes. Segundo, se pretende mejorar la baja fiabilidad y robustez de las redes de sensores inal谩mbricos con nodos m贸viles. Con este objetivo se presenta un m茅todo que combina RPL con un sistema de enrutado que considera la posici贸n de los nodos basado en el filtro de Kalman. 脡ste combina la eficiencia y fiabilidad de RPL permitiendo adem谩s manejar nodos m贸viles. Tercero, se estudian maneras de proporcionar la calidad de servicio necesaria a las redes de sensores con tr谩fico heterog茅neo. Para ello se propone una estrategia multi 谩rbol basada en la construcci贸n de m煤ltiples instancias RPL. 脡sta construye diferentes topolog铆as virtuales para cada funci贸n objetivo, y de esta manera es posible atender los requisitos de cada flujo de tr谩fico de manera independiente. Finalmente, se estudia la manera de integrar las redes de sensores inal谩mbricos dentro de la nube y el internet de las cosas. Con este objetivo se propone una formulaci贸n para coordinar la utilizaci贸n de los recursos de la red de manera conjunta usando estrategias de virtualizaci贸n y computaci贸n m贸vil en la nube. Esto permite reducir el consumo energ茅tico de la red, teniendo en cuenta las capacidades y limitaciones de cada nodo, satisfaciendo tanto los requisitos de los diferentes servicios como los de los usuarios.Wireless sensor networks (WSNs) are expected to revolutionize the way we live, work, and interact with the physical environment. Although WSNs have been in the spotlight of the research community for the last decade, their performance in practical implementations is still far behind the theoretical results. This is mainly due to the practical issues that arise in real-life scenarios. As a result, WSNs are generally limited to simple environmental sensing applications. The aim of this thesis is to reduce the gap between the theoretical and real potential of WSNs, and therefore increase their integration in society. In particular, this thesis focuses on the following four practical obstacles: high node density, node mobility, traffic heterogeneity and integration with the future Internet of Things (IoT). First, we deal with the interference problem in high density sensor deployments. We address this issue proposing a pragmatic joint routing, transmission power control and channel allocation approach, built upon the well-known RPL (Routing Protocol for Low-Power and Lossy Networks). This reduces the average packet collisions and the energy consumption of WSNs. Second, we address the low communication reliability and robustness in WSNs with mobile nodes. In particular, we propose a solution that combines RPL with a position-based routing approach based on Kalman filtering. This provides the efficiency and reliability of RPL, and also includes mobility support for non-static nodes. Third, we study the problem of QoS (Quality of Service) provisioning in WSNs managing heterogeneous traffic. With this in mind, we propose a multi-tree approach based on the construction of multiple RPL Instances. This constructs multiple virtual topologies to address the particular requirements of each traffic flow individually. Finally, we focus on the efficient integration of wireless sensors with Cloud-based IoT platforms. In particular, we propose a formulation to orchestrate the resource utilization of the whole network, taking advantage of the recent advances in virtualization and mobile cloud computing. This optimizes the overall consumption, considering the capabilities and limitations of each node, while satisfying the service requirements and the individual users' demands

    Addressing mobility in RPL with position assisted metrics

    No full text
    Mobility is still an open challenge in wireless sensor networks (WSNs). Energy efficient routing strategies designed for static WSNs, such as routing protocol for low-power and lossy networks (RPL), generally have a slow response to topology changes. Moreover, their high signalling cost to keep up-to-date routes in the presence of mobile nodes makes them inefficient in these scenarios. In this paper, we introduce Kalman positioning RPL (KP-RPL), a novel routing strategy for WSNs with both static and mobile nodes, based on RPL. The objective of KP-RPL is to provide robust and reliable routing, considering the positioning inaccuracies and node disconnections that arise in real-life WSNs. This considers the original RPL for the communication among static nodes and position-based routing for mobile nodes, which use a novel RPL metric that combines Kalman positioning and blacklisting. The simulation results show that the reliability and the robustness of the network in harsh conditions are enhanced compared with geographical routing. Moreover, KP-RPL reduces the density and the number of simultaneously active anchor nodes for positioning. As a result, the infrastructure cost is lower, and the network lifetime is extended

    Cooperative strategies for imperfect CSI scenarios based on distributed Alamouti

    No full text
    Les comunicacions cooperatives estan guanyant un gran inter猫s en les comunicacions modernes degut a que permeten millorar la transmissi贸 d始informaci贸 entre un emissor i un receptor utilitzant una s猫rie de terminals situats entre ells. Aquest projecte 茅s un estudi complet del sistemes cooperatius, analitzant el seu rendiment i comparant l始煤s d始un sol d始aquests terminals amb l始煤s del codi Alamouti, que utilitza dos terminals. Primer hi ha una introducci贸 als sistemes cooperatius i a la teoria de la informaci贸. Despr茅s hem estudiat un sistema cooperatiu amb la teoria de la informaci贸 com a base, en termes de probabilitat de fallada del sistema, i posteriorment l始hem adaptat a un sistema cooperatiu real utilitzant una modulaci贸 QPSK, estudiant la seva probabilitat d始error de paquet. Finalment es proposen diversos protocols que permeten millorar el rendiment del sistema cooperatiu estudiat.Las comunicaciones cooperativas est谩n ganando mucho inter茅s en las comunicaciones modernas debido a que permiten mejorar la transmisi贸n de informaci贸n entre un emisor y un receptor usando una serie de terminales intermedios. Este proyecto es un estudio completo de los sistemas cooperativos, analizando su rendimiento y comparando el uso de uno solo de estos terminales con el uso del c贸digo Alamouti, el cual usa dos terminales. Primero hay una introducci贸n a los sistemas cooperativos y a la teor铆a de la informaci贸n. Despu茅s hemos estudiado un sistema cooperativo con la teor铆a de la informaci贸n como base, en t茅rminos de probabilidad de fallo del sistema, y posteriormente lo hemos adaptado a un sistema cooperativo real usando una modulaci贸n QPSK, estudiando su probabilidad de error de paquete. Finalmente se proponen varios protocolos que permiten mejorar el rendimiento del sistema cooperativo estudiado.Cooperative communications are gaining much interest in modern communications because they allow to improve the information transmission between a source and a destination using various intermediate terminals. This project is a complete study of cooperative systems, analyzing its performance and comparing the use of a single terminal with the use of the Alamouti code, which uses two terminals. First, there is an introduction to cooperative systems and to information theory. Then we have studied a cooperative system using the information theory, in terms of outage probability, and subsequently we have adapted it to a real cooperative system using a QPSK modulation, studying its packet error probability. Finally several protocols are proposed to improve the performance of the studied cooperative system
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