7 research outputs found

    MIMO Systems

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    In recent years, it was realized that the MIMO communication systems seems to be inevitable in accelerated evolution of high data rates applications due to their potential to dramatically increase the spectral efficiency and simultaneously sending individual information to the corresponding users in wireless systems. This book, intends to provide highlights of the current research topics in the field of MIMO system, to offer a snapshot of the recent advances and major issues faced today by the researchers in the MIMO related areas. The book is written by specialists working in universities and research centers all over the world to cover the fundamental principles and main advanced topics on high data rates wireless communications systems over MIMO channels. Moreover, the book has the advantage of providing a collection of applications that are completely independent and self-contained; thus, the interested reader can choose any chapter and skip to another without losing continuity

    Proceedings of the Third International Mobile Satellite Conference (IMSC 1993)

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    Satellite-based mobile communications systems provide voice and data communications to users over a vast geographic area. The users may communicate via mobile or hand-held terminals, which may also provide access to terrestrial cellular communications services. While the first and second International Mobile Satellite Conferences (IMSC) mostly concentrated on technical advances, this Third IMSC also focuses on the increasing worldwide commercial activities in Mobile Satellite Services. Because of the large service areas provided by such systems, it is important to consider political and regulatory issues in addition to technical and user requirements issues. Topics covered include: the direct broadcast of audio programming from satellites; spacecraft technology; regulatory and policy considerations; advanced system concepts and analysis; propagation; and user requirements and applications

    Adaptive Non-Linear Digital Self-Interference Cancellation for Full-duplex Wireless Systems Using Ito-Hermite Polynomials

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    In this paper, a novel non-linear digital self- interference cancellation algorithm is proposed for full-duplex wireless systems. The proposed algorithm constructs a replica of the nonlinearly-distorted transmitted signal using Itô generalization of the Hermite (Itô-Hermite) polynomials. Because Itô-Hermite polynomials constitute orthogonal basis functions of any non-linear function when the input is a complex Gaussian random process, the proposed least mean squares (LMS) adaptive filtering based on Itô-Hermite polynomials optimally cancels non-linearly distorted self-interference signals in full-duplex systems. From numerical results, it is shown that the proposed algorithm provides noticeable gains in terms of both a fast convergence rate and the low computational complexity for the self-interference cancellation compared to the existing LMS algorithm using Volterra- series as basis functions with basis function pre- orthogonalization. © 2018 IEEE.1

    Multimode fibre broadband access and self-referencing sensor networks

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    Future Internet Access technologies are supposed to bring us a very performing connection to the main door of our homes. At the same time, new services and devices and their increase use will require data transfers at speeds exceeding 1Gbps inside the building or home at the horizon 2012. Both drivers lead to the deployment of a high-quality, futureproof network inside buildings and homes. This environment may end up taking advantage of optical cabling solutions as an alternative to more traditional copper or pure wireless approaches. Related to this latter fact, the objectives of this work are: • The achievement of a full convergence scenario between optical networks from the telecommunication services providers to the end users underscores the necessity of accurate and realistic fibre models in assessing the performance of broadband access networks with the premises of high-capacity and total compatibility. Silicabased MMFs and PF GIPOFs are the most promising candidates for such a convergence within the in-building/home scenario. Contributions to a better understanding of the possibilities of signal transmission outside the baseband of such fibres are investigated, in order to extend their capabilities, together with the evaluation of current fibre frequency response theoretical models by means of an extensive set of measurements. • The achievement of a full convergence scenario between optical networks from the telecommunication services providers to the end users is also contingent on research and development in the field of optical fibre sensors, mainly driven by the growing demand of fully building/home and industry automation, leading to a reliable integration of the optical networks. Related to this, development of multiplexing and measurement techniques for fibre-optic intensity-based sensors are analyzed and experimentally investigated. In the sensor network topology proposed, by replacing the fibre delay line with an electronic delay in the reception stage, it is possible to avoid long fibre delay coils in the remote sensing points and achieving a compact, flexible and re-configurable self-referencing technique. Applications in both scenarios can be considered, on the one hand the in-building/home network and on the other hand the WDM-PON access network topology through which operators provision the different services. -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------La demanda e incursión en la sociedad de nuevos servicios multimedia, tales como televisión por Internet (IPTV, Internet Protocol Television) o video-bajo-demanda (VoD, Video on Demand) junto con el incremento del tráfico de datos requerido para nuevas aplicaciones como la televisión por alta definición (HDTV, High-Definition Television) y transferencias P2P (Peer-to-Peer) exigen un aumento de la capacidad de las redes de datos desplegadas hoy en día. Para hacer frente a este aumento de la demanda de capacidad de las redes de acceso, los proveedores de estos servicios multimedia están reemplazando las infraestructuras de las redes de acceso basadas en cable coaxial, tales como xDSL (x- Digital Subscriber Line), por otras nuevas de mayor capacidad desplegadas en fibra óptica, permitiendo la interconexión de los nodos de red con los múltiples hogares y negocios de los abonados, constituyendo el núcleo de lo que es conocido como “fibra hasta el hogar/nodo/edificio” o redes FTTx. Tradicionalmente el despliegue de las redes ópticas se ha realizado mediante fibra óptica monomodo de sílice (SMF, Singlemode Fibre). Ello es debido a su gran ancho de banda que permite una gran capacidad de transporte de servicios y datos. Es por ello que en base a este tipo de fibra se ha realizado el despliegue de redes de distribución y metropolitanas y, de un tiempo a esta parte, incluso penetrando su instalación en las redes de acceso. Junto con lo anteriormente expuesto, existe una necesidad de convergencia de servicios e infraestructuras dentro de las redes de acceso. Actualmente, cables coaxiales, par trenzado de cobre e incluso señales inalámbricas se encuentran entremezcladas dentro del hogar proporcionando servicios diferentes con apenas cooperación entre ellos. Una infraestructura común dentro del hogar en el que una gran cantidad de servicios pudieran ser integrados y soportados por la misma sería un aspecto deseable. Y es más, frente a las desventajas de infraestructuras basadas en cable de cobre (cable coaxial y par trenzado) como son susceptibilidad a interferencias electromagnéticas, presencia de crosstalk y relativa baja capacidad de transporte de datos, las fibras ópticas (tanto en su versión monomodo como multimodo) presentan las ventajas de un menor volumen, mayor flexibilidad y menor peso junto con una capacidad mayor de transmisión de datos sobre distancias mayores. Es por esto que éstas últimas constituyen la base para las futuras redes de acceso en el hogar

    Safety and Reliability - Safe Societies in a Changing World

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    The contributions cover a wide range of methodologies and application areas for safety and reliability that contribute to safe societies in a changing world. These methodologies and applications include: - foundations of risk and reliability assessment and management - mathematical methods in reliability and safety - risk assessment - risk management - system reliability - uncertainty analysis - digitalization and big data - prognostics and system health management - occupational safety - accident and incident modeling - maintenance modeling and applications - simulation for safety and reliability analysis - dynamic risk and barrier management - organizational factors and safety culture - human factors and human reliability - resilience engineering - structural reliability - natural hazards - security - economic analysis in risk managemen

    Proceedings of the 19th Sound and Music Computing Conference

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    Proceedings of the 19th Sound and Music Computing Conference - June 5-12, 2022 - Saint-Étienne (France). https://smc22.grame.f
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