Caracterización experimental de canales direccionales de Radio a 5.5, 3.3 y 2.4 GHz en diferentes entornos

El objetivo de este Trabajo de Fin de Grado es el de realizar una campaña de medidas para el cálculo de las pérdidas de propagación en diferentes escenarios interiores del Edificio C de la Escuela Politécnica Superior a tres frecuencias distintas, 5.5 GHz, 3.3 GHz y 2.4 GHz, y a tres alturas distintas: 1 metro, 1.4 metros y 1.8 metros. Se estudiarán enlaces de 10 y 20 metros de distancia total entre antenas evaluando el efecto que producen el tipo de paredes, las personas o la existencia de mobiliario en los distintos escenarios. Las medidas se realizarán utilizando señales de onda continua que serán transmitidas por una de las antenas y recibida por la otra. Esta señal será analizada por el analizador de redes. Los resultados se mostrarán: -En forma de gráfica y contarán con: los datos de las medidas tomadas, la atenuación teórica, el ajuste de las medidas en dos rectas, el histograma de la diferencia de medidas al valor medio y su función de probabilidad. Las funciones de distribución en todos los casos se han aproximado por una combinación de una función Gaussiana y una función de Rayleigh. -En forma de ecuación (modelo de propagación) que define el ajuste de las medidas en dos rectas.The aim of this project is to carry out a measurement campaign focused on the calculation of propagation loss different indoor in Escuela Politécnica Superior. I will work with three different frequencies (5.5 GHz, 3.3 GHz and 2.4 GHz) and three different heights: 1m, 1.4m y 1.8m. In this study I will do 10 and 20 meters wireless links, which depend on the scenario. I will evaluate the effect that produce the type of walls, people or piece of furniture in different scenarios. The measurements will be made by using continuous wave signals to be transmitted by one antenna and received by the other. This signal is analyzed by the network analyzer. The results will show: -Graphical data that will have: measures data, theorical loss, two curves adjustment, measurements to mean value histogram, and its cumulative distribution function. The cumulative distribution functions will be aproximated by a combination of at least one Gaussian functions and one Rayleigh function. -Propagation model that is defined with two curves equations

Advanced Trends in Wireless Communications

Physical limitations on wireless communication channels impose huge challenges to reliable communication. Bandwidth limitations, propagation loss, noise and interference make the wireless channel a narrow pipe that does not readily accommodate rapid flow of data. Thus, researches aim to design systems that are suitable to operate in such channels, in order to have high performance quality of service. Also, the mobility of the communication systems requires further investigations to reduce the complexity and the power consumption of the receiver. This book aims to provide highlights of the current research in the field of wireless communications. The subjects discussed are very valuable to communication researchers rather than researchers in the wireless related areas. The book chapters cover a wide range of wireless communication topics

A New Hypo-Rayleigh Distribution for Short Range Wide-Band Directive Indoor Channel Fading Modeling at 3.3 and 5.5 GHz Bands

The final publication is available at Springer via http://dx.doi.org/10.1007/s11277-015-2879-zIn this work, propagation loss models for indoor environment are presented. The directive channel propagation loss in indoor environment at frequency bands of 3.3 GHz with a channel bandwidth of 200 MHz and 5.5 GHz band with 320 MHz bandwidth is measured using vertical polarizations where a set of directive panel antennas and a network analyzer are used in the measurement campaign. It is noticed that, the propagation loss can be modelled by two slopes propagation model giving a rise to two propagation zones. The first zone of propagation is almost free space propagation zone while generally; the second zone has a higher deviation from the mean value of propagation loss. A new Hypo-Rayleigh distribution is proposed to model the channel induced fading in the second zone of the propagation zones

Novel compact antenna designs for future wireless communication systems

Wireless and mobile devices are becoming packed with more applications that require an increasing number of communication technologies as well as a constant desire for size reduction. Ideally, every single communication technology should have a dedicated antenna system. This puts pressure on antenna engineers as the available space for the radiation elements is becoming very limited, particularly for small mobile phones and small cell base stations. Traditionally, reducing the size of the antenna was enough to accommodate these requirements. However, making antennas smaller strongly affects their performance. In order to further shrink a multi-radio transmitting system, antenna reconfiguration provides an option to converge multiple radiating elements into a single one, and hence, save space in wireless and mobile devices. The creation of novel materials such as carbon nanotubes, graphene and metamaterials, which present extraordinary electrical and mechanical properties, has opened new possibilities within the antenna field. The most interesting properties of these materials are the presence of plasmons in carbon nanotubes and graphene at much lower frequencies than in metals, the ability to tune the surface impedance of graphene by applying a DC voltage bias and the possibility of generating size-independent resonances in metamaterials. These materials are studied here as alternative methods to achieve antenna size reduction and reconfigurability at microwave frequencies. This thesis presents an initial study of the advantages and disadvantages of designing small and reconfigurable antennas fully made of carbon nanotubes and graphene at microwave, millimetre wave and terahertz frequencies. Here, the focus is on the trade-offs between the antenna performance and the achievable size reduction and reconfigurability at microwave frequencies. The results show that the resulting low antenna efficiencies do not compensate the small size reduction and reconfigurability of these antennas at such frequencies. This is mainly caused by the large losses suffered in carbon nanotubes and graphene and the low inductive behaviour of these materials at microwave frequencies. Furthermore, carbon nanotubes present extremely high input impedances, which make the antenna matching very difficult, with little reconfigurability due to not being able to actively tune their resistivity and the infeasibility of using plasmons at frequencies for commercial applications (up to 10 GHz). For this reason, three planar hybrid antennas made of a traditional conductor (i.e. copper) and graphene are presented as the main proposed solutions for antenna reconfigurability and size reduction at microwave frequencies. The first proposed design provides frequency reconfigurability by changing the electrical length of microstrip patch antennas using the variable surface impedance of graphene. However, the resulting antenna efficiencies are low compared to other reconfigurable antennas found in the literature. The second design provides polarization reconfigurability by adding graphene sheets to the truncated corners of a square patch antenna. The resulting antenna efficiencies are improved when compared to the first antenna design. This is achieved because the impact of graphene on the antenna efficiency is reduced due to the use of graphene sheets with smaller size. The final design combines size reduction and frequency reconfigurability. Size reduction is achieved by designing a zeroth order resonant (ZOR) antenna, while frequency reconfigurability is achieved by tuning the surface impedance of graphene. The variable surface impedance of graphene changes the inductive and capacitive behaviour of the ZOR antenna which in turns changes its resonant frequency. The resulting antenna efficiencies are better compared to the first design but worse than in the second design. Additional features presented by the first and third proposed antenna designs are the ability to tune the reflection coeficient and antenna bandwidth, which might help to reduce the complexity of the matching network; and to select any intermediate resonant frequency between two edge frequencies. The latter property which might be useful to compensate undesired effects in wearable antennas, by selecting appropriate values of the surface impedance of graphene. In addition, an analysis of the power consumed in the proposed reconfigurable antennas is also provided when switching between different values of the surface impedance of graphene. Finally, the proposed antenna designs are also evaluated as fully transparent and flexible reconf-gurable antennas which allows integration in scenarios where flexibility and transparency are a requirement or an advantage

Full Proceedings, 2018

Full conference proceedings for the 2018 International Building Physics Association Conference hosted at Syracuse University

Shortest Route at Dynamic Location with Node Combination-Dijkstra Algorithm

Abstract— Online transportation has become a basic requirement of the general public in support of all activities to go to work, school or vacation to the sights. Public transportation services compete to provide the best service so that consumers feel comfortable using the services offered, so that all activities are noticed, one of them is the search for the shortest route in picking the buyer or delivering to the destination. Node Combination method can minimize memory usage and this methode is more optimal when compared to A* and Ant Colony in the shortest route search like Dijkstra algorithm, but can’t store the history node that has been passed. Therefore, using node combination algorithm is very good in searching the shortest distance is not the shortest route. This paper is structured to modify the node combination algorithm to solve the problem of finding the shortest route at the dynamic location obtained from the transport fleet by displaying the nodes that have the shortest distance and will be implemented in the geographic information system in the form of map to facilitate the use of the system. Keywords— Shortest Path, Algorithm Dijkstra, Node Combination, Dynamic Location (key words

Safety and Reliability - Safe Societies in a Changing World

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