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Yes / 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.

Ultra-wideband (UWB) communication is emerging as a new wireless technology, which promises high data rates with low interference and low power consumption. The development of such UWB systems requires a sufficiently large amount of data to characterize the propagation behavior of UWB signals in indoor environments and develop accurate channel models. This thesis focuses primarily on a frequency-domain approach for propagation measurements and characterization of indoor UWB channels. This approach is based on measurements of the amplitude using a scalar network analyzer and retrieval of the phase from the amplitude data using a Hilbert transform relationship. Extensive propagation data are collected in a frequency range of 1 to 12 GHz in two buildings on Virginia Tech campus. Using the data, channel characterization results are obtained and compared to those based on time-domain measurements. Some statistical results for small-scale fading, path loss exponent, and signal quality are presented. This comparison validates the accuracy of measured results for the UWB measurement campaign. The measured data also reaffirms the immunity of UWB propagation to small-scale fading which is present in narrowband wireless communication systems. In addition to channel propagation measurements, signal distortions in UWB links, due to bandwidth limitations of antenna characteristics as well as the dispersive behavior of building materials, are also examined. In particular, the distortion of radiated signals by TEM horn antennas along off-boresight directions are studied experimentally. Furthermore, pulse distortions resulting from propagation through dispersive walls are demonstrated by simulation. The roles of receive-transmit antennas in a UWB link are examined, and the requirements for gain, input impedance, polarization, and phase of the radiated signal necessary for minimization of signal distortions are pointed out. / Master of Science

Implanted Devices are important components of the Wireless Body Area Network (WBAN) as a promising technology in biotelemetry, e-health care and hyperthermia applications. The design of WBAN faces many challenges, such as frequency band selection, channel modeling, antenna design, physical layer (PHY) protocol design, medium access control (MAC) protocol design and power source. This research focuses on the design of implanted antennas, channel modeling between implanted devices and Wireless Power Transfer (WPT) for implanted devices. An implanted antenna needs to be small while it maintains Specific Absorption Rate (SAR) and is able to cope with the detuning effect due to the electrical properties of human body tissues. Most of the proposed antennas for implanted applications are electric field antennas, which have a high near-zone electric field and, therefore, a high SAR and are sensitive to the detuning effect. This work is devoted to designing a miniaturized magnetic field antenna to overcome the above limitations. The proposed Electrically Coupled Loop Antenna (ECLA) has a low electric field in the near-zone and, therefore, has a small SAR and is less sensitive to the detuning effect. The performance of ECLA, channel model between implanted devices using Path Loss (PL) and WPT for implanted devices are studied inside different human body models using simulation software and validated using experimental work. The study is done at different frequency bands: Medical Implanted Communication Services (MICS) band, Industrial Scientific and Medical (ISM) band and 3.5 GHz band using ECLA. It was found that the proposed ECLA has a better performance compared to the previous designs of implanted antennas. Based on our study, the MICS band has the best propagation channel inside the human body model among the allowed frequency bands. The maximum PL inside the human body between an implanted antenna and a base station on the surface is about 90 dB. WPT for implanted devices has been investigated as well, and it has been shown that for a device located at 2 cm inside the human body with an antenna radius of 1 cm an efficiency of 63% can be achieved using the proposed ECLA. / Ph. D.

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. / Master of Science

The traditional way of increasing capacity in a wirelesscommunication system has been cell splitting and fixedchannel-allocation based on prediction tools. However, theplanning complexity increases rapidly with the number of cellsand the method is not suitable for the large temporal andspatial traffic variations expected in the future. A lot ofresearch has therefore been performed regarding adaptivechannel allocation, where a channel can be used anywhere aslong as the signal-to-interference ratio (SIR) is acceptable. Acommon opinion is that these solutions must be decentralizedsince a centralized one would be overly complex. In this thesis, we study the locally centralizedbunch conceptfor radio resource management (RRM) in aManhattan environment and show that it can give a very highcapacity both for outdoor users and for indoor users covered byoutdoor base stations. We show how measurement limitations anderrors affect the performance and wepropose methods to handlethese problems, e.g. averaging of measured values, robustchannel selection algorithms, and increased SIR margins. Wealso study the computational and signaling complexities andshow that they can be reduced by splitting large bunches, usingsparse matrix calculations, and by using a simplified admissionalgorithm. However, a reduction of the complexity often means areduction of the system capacity. The measurements needed for RRM can also be used to find amobile terminal's geographical position. We propose and studysome simple yet accurate methods for this purpose. We alsostudy if position information can enhance RRM as is oftensuggested in the literature. In the studied scenario, thisinformation seems to be of limited use. One possible use is toestimate the mobile user's speed, to assist handover decisions.Another use is to find the location of user hotspots in anarea, which is beneficial for system planning. Our results show that the bunch concept is a promisingcandidate for radio resource management in future wirelesssystems. We believe that the complexity is manageable and themain price we have to pay for high capacity is frequentreallocation of connections. <b>Keywords:</b>bunch concept, radio resource management,network-assisted resource management, base station selection,dynamic channel allocation, DCA, channel selection,least-interfered, interference avoidance, interferenceaveraging, handover, power control, path-loss measurements,signal strength, link-gain matrix, TD-CDMA, UTRA TDD, Manhattanscenario, microcells, mobile positioning, position accuracy,trilateration, triangulation, speed estimation

<p>The traditional way of increasing capacity in a wirelesscommunication system has been cell splitting and fixedchannel-allocation based on prediction tools. However, theplanning complexity increases rapidly with the number of cellsand the method is not suitable for the large temporal andspatial traffic variations expected in the future. A lot ofresearch has therefore been performed regarding adaptivechannel allocation, where a channel can be used anywhere aslong as the signal-to-interference ratio (SIR) is acceptable. Acommon opinion is that these solutions must be decentralizedsince a centralized one would be overly complex.</p><p>In this thesis, we study the locally centralized<i>bunch concept</i>for radio resource management (RRM) in aManhattan environment and show that it can give a very highcapacity both for outdoor users and for indoor users covered byoutdoor base stations. We show how measurement limitations anderrors affect the performance and wepropose methods to handlethese problems, e.g. averaging of measured values, robustchannel selection algorithms, and increased SIR margins. Wealso study the computational and signaling complexities andshow that they can be reduced by splitting large bunches, usingsparse matrix calculations, and by using a simplified admissionalgorithm. However, a reduction of the complexity often means areduction of the system capacity.</p><p>The measurements needed for RRM can also be used to find amobile terminal's geographical position. We propose and studysome simple yet accurate methods for this purpose. We alsostudy if position information can enhance RRM as is oftensuggested in the literature. In the studied scenario, thisinformation seems to be of limited use. One possible use is toestimate the mobile user's speed, to assist handover decisions.Another use is to find the location of user hotspots in anarea, which is beneficial for system planning.</p><p>Our results show that the bunch concept is a promisingcandidate for radio resource management in future wirelesssystems. We believe that the complexity is manageable and themain price we have to pay for high capacity is frequentreallocation of connections.</p><p><b>Keywords:</b>bunch concept, radio resource management,network-assisted resource management, base station selection,dynamic channel allocation, DCA, channel selection,least-interfered, interference avoidance, interferenceaveraging, handover, power control, path-loss measurements,signal strength, link-gain matrix, TD-CDMA, UTRA TDD, Manhattanscenario, microcells, mobile positioning, position accuracy,trilateration, triangulation, speed estimation</p>

The radio wave propagation prediction is one of the key elements for designing an efficient radio network system. WRAP International has developed a software for spectrum management and radio network planning.This software includes some wave propagation models which are used to predict path loss. Current propagation models in WRAP perform the calculation in a vertical 2D plane, the plane between the transmitter and the receiver. The goal of this thesis is to investigate and implement a 3D wave propagation model, in a way that reflections and diffractions from the sides are taken into account.The implemented 3D wave propagation model should be both fast and accurate. A full 3D model which uses high resolution geographical data may be accurate, but it is inefficient in terms of memory usage and computational time. Based on the fact that in urban areas the strongest path between the receiver and the transmitter exists with no joint between vertical and horizontal diffractions [10], the radio wave propagation can be divided into two parts, the vertical and horizontal part. Calculations along the horizontal and vertical parts are performed independently, and after that, the results are combined. This approach leads to less computational complexity, faster calculation time, less memory usage, and still maintaining a good accuracy.The proposed model is implemented in C++ and speeded up using parallel programming techniques. Using the provided Stockholm high resolution geographical data, simulations are performed and results are compared with real measurements and other wave propagation models. In addition to the path loss calculation, the proposed model can also be used to estimate the channel power delay profile and the delay spread.

This Master´s thesis focuses on design and implementation of programmable attenuator. The main aim of this thesis is to create an electronical device that provide continuous setting of attenuation value in the range between 0–150 dB. Setting a value from the range can be performed using buttons and set values are shown on display. For this thesis an attenuator with working frequency between 0–6 GHz was chosen and four–layer printed circuit board was designed. As a result the device is fitted with an 8bit microcontroller ATmega328P–PU using five 6bit digital attenuators connected in series with manual and program settings of attenuation from 0–157,5 dB with step of 0,5 dB. Data are shown on a build–in display. The application for remote settings and value reading over integrated USB (Universal Serial Bus) interface, was created in C#. In conclusion of this thesis there is a measurement evaluation of attenuation measurement performed on the device.

[ES] La quinta generación de comunicaciones móviles, 5G, promete ser una revolución tecnológica que vaya más allá de multiplicar la velocidad de transmisión de datos de sus predecesoras. Pretende soportar una gran cantidad de dispositivos y alcanzar latencias muy cercanas a 1 milisegundo. Para satisfacer estos ambiciosos requisitos, se han investigado nuevas tecnologías habilitadoras. Una de ellas es el uso de las bandas de ondas milimétricas (mmW) en las cuales hay una gran cantidad de espectro disponible. Para predecir las características del canal radio y evaluar las prestaciones de la 5G de forma fiable en las bandas mmW se requieren modelos de canal complejos. Concretamente, los modelos de propagación más precisos son los basados en trazado de rayos, pero su alto costo computacional los hacen inviables para la caracterización del canal radio en escenarios complejos. Por otro lado, en los últimos años, la tecnología de videojuegos ha desarrollado potentes herramientas para modelar la propagación de la luz en escenarios superrealistas. Dada la cercanía espectral entre el espectro visible y las ondas mmW, la presente Tesis ha estudiado la aplicación de las herramientas de modelado de propagación de la luz de los motores de juego para el modelado del canal radio en mmW. Esta Tesis propone un modelo de estimación de las pérdidas de propagación en mmW llamado "Modelo de Intensidad de Luz'' (LIM). Usando este modelo, basado en los procesos de iluminación realizados por los motores de juego, los transmisores de señal se sustituyen por focos de luz y la intensidad lumínica recibida en un punto se traduce a potencia de señal en milimétricas a través de una función polinómica sencilla. Una de las ventajas de usar los motores de juego es su gran capacidad y la facilidad que tiene el usuario para crear escenarios superrealistas que representen fielmente la geometría de escenarios donde se quiera evaluar el canal radio. De esta forma se pueden obtener estimaciones precisas de las pérdidas de propagación. La estimación de las pérdidas de propagación con LIM ha sido comparada con campañas de medida en las bandas de 28 GHz y 73 GHz y con otros modelos de propagación. Como resultado, el error de estimación de LIM es menor que los modelos estocásticos actuales y es comparable con el modelo de trazado de rayos. Y, además, el coste computacional de LIM comparado con el trazado de rayos es 130 veces menor, lo que posibilita el uso de LIM en escenarios altamente complejos para la estimación del canal radio en tiempo real. Los motores de juego permiten caracterizar de forma diferente la interacción de los materiales con la luz configurando el mapa de normales de sus superficies y sus funciones de dispersión y reflexión. En esta Tesis se ha determinado la caracterización de varios materiales que mejor se ajusta a medidas de laboratorio realizadas en un escenario controlado en la banda de 28 GHz. El modelo de LIM empleando materiales con esta caracterización óptima reduce más de un 50\% su error de estimación con respecto a la aplicación de LIM con los materiales por defecto, mientras que su coste computacional sigue siendo 26 veces menor que el modelo de trazado de rayos. Finalmente, se ha desarrollado sobre un motor de juego una primera versión de plataforma para la emulación de los sistemas 5G que es el punto de partida para un emulador completo de 5G. Esta plataforma no sólo contiene el modelo de LIM sino que incluye varios casos de uso de la 5G en entornos superrealistas. La plataforma, que se basa en el concepto de "Serious Game Engineering", rompe las limitaciones de los simuladores de redes móviles en cuanto a las capacidades de visualización e interacción del usuario con los componentes de la red en tiempo real. / [CAT] La cinquena generació de comunicacions mòbils, 5G, promet ser una revolució tecnològica que vaja més enllà de multiplicar la velocitat de transmissió de dades de les seues predecessores. Pretén suportar una gran quantitat de dispositius i aconseguir latències molt pròximes a 1 mil·lisegon. Per a satisfer aquests ambiciosos requisits, s'han investigat noves tecnologies habilitadores. Una d'elles és l'ús de les bandes d'ones mil·limètriques (mmW) en les quals hi ha una gran quantitat d'espectre disponible. Per a predir les característiques del canal ràdio i avaluar les prestacions de la 5G de forma fiable en les bandes mmW es requereixen models de canal complexos. Concretament, els models de propagació més precisos són els basats en traçat de rajos, però el seu alt cost computacional els fan inviables per a la caracterització del canal ràdio en escenaris complexos. D'altra banda, en els últims anys, la tecnologia de videojocs ha desenvolupat potents eines per a modelar la propagació de la llum en escenaris superrealistes. Donada la proximitat espectral entre l'espectre visible i les ones mmW, la present Tesi ha estudiat l'aplicació de les eines de modelatge de propagació de la llum dels motors de joc per al modelatge del canal radie en mmW. Aquesta Tesi proposa un model d'estimació de les pèrdues de propagació en mmW anomenat "Model d'Intensitat de Llum'' (LIM). Usant aquest model, basat en els processos d'il·luminació realitzats pels motors de joc, els transmissors de senyal se substitueixen per focus de llum i la intensitat lumínica rebuda en un punt es tradueix a potència de senyal en mil·limètriques a través d'una funció polinòmica senzilla. Una dels avantatges d'usar els motors de joc és la seua gran capacitat i la facilitat que té l'usuari per a crear escenaris superrealistes que representen fidelment la geometria d'escenaris on es vulga avaluar el canal ràdio. D'aquesta forma es poden obtindre estimacions precises de les pèrdues de propagació. L'estimació de les pèrdues de propagació amb LIM ha sigut comparada amb campanyes de mesura en les bandes de 28~GHz i 73~GHz i amb altres models de propagació. Com a resultat, l'error d'estimació de LIM és menor que els models estocàstics actuals i és comparable amb el model de traçat de rajos. I, a més, el cost computacional de LIM comparat amb el traçat de rajos és 130 vegades menor, la qual cosa possibilita l'ús de LIM en escenaris altament complexos per a l'estimació del canal ràdio en temps real. Els motors de joc permeten caracteritzar de forma diferent la interacció dels materials amb la llum configurant el mapa de normals de les seues superfícies i les seues funcions de dispersió i reflexió. En aquesta Tesi s'ha determinat la caracterització de diversos materials que s'ajusta millor a mesures de laboratori realitzades en un escenari controlat en la banda de 28 GHz. El model de LIM emprant materials amb aquesta caracterització òptima redueix més d'un 50 % el seu error d'estimació respecte a l'aplicació de LIM amb els materials per defecte, mentre que el seu cost computacional continua sent 26 vegades menor que el model de traçat de rajos. Finalment, s'ha desenvolupat sobre un motor de joc una primera versió de plataforma per a l'emulació dels sistemes 5G que és el punt de partida per a un emulador complet de 5G. Aquesta plataforma no solament conté el model de LIM sinó que inclou diversos casos d'ús de la 5G en entorns superrealistes. La plataforma, que es basa en el concepte de "Serious Game Engineering", trenca les limitacions dels simuladors de xarxes mòbils quant a les capacitats de visualització i interacció de l'usuari amb els components de la xarxa en temps real. / [EN] The fifth generation of mobile communications, 5G, promises to be a technological revolution that goes beyond multiplying the data transmission speed of its predecessors. It aims to support a large number of devices and reach latencies very close to 1 millisecond. To meet these ambitious requirements, new enabling technologies have been researched. One of these is the use of millimetre-wave bands (mmW) in which a large amount of spectrum is available. Complex channel models are required to predict radio channel characteristics and reliably evaluate 5G performance in the mmW bands. Specifically, the most accurate propagation models are those based on ray tracing, but their high computational cost makes them unfeasible for radio channel characterization in complex scenarios. On the other hand, in recent years, video game technology has developed powerful tools to model the propagation of light in super realistic scenarios. Given the spectral closeness between the visible spectrum and the mmW waves, the present Thesis has studied the application of light propagation modeling tools from game engines for radio channel modeling in mmW. This Thesis proposes a model for estimating propagation losses in mmW called "Light Intensity Model'' (LIM). Using this model, based on the lighting processes performed by the game engines, the signal transmitters are replaced by light sources and the light intensity received at a point is translated into signal strength in mmW through a simple polynomial function. One of the advantages of using the game engines is their great capacity and the ease with which the user can create super realistic scenarios that faithfully represent the geometry of scenarios where the radio channel is to be evaluated. In this way, accurate estimates of propagation losses can be obtained. The estimation of propagation losses with LIM has been compared with measurement campaigns in the 28 GHz and 73 GHz bands and with other propagation models. As a result, the LIM estimation error is smaller than the current stochastic models and is comparable with the ray tracing model. In addition, the computational cost of LIM compared to ray tracing is 130 times lower, allowing the use of LIM in highly complex scenarios for real-time radio channel estimation. The game engines allow to characterize in a different way the interaction of the materials with the light configuring the normal map of their surfaces and their scattering and reflection functions. In this Thesis it has been determined the characterization of several materials that best fits to laboratory measurements made in a controlled scenario in the 28 GHz band. The LIM model using materials with this optimal characterization reduces by more than 50% its estimation error with respect to the application of LIM with default materials, while its computational cost remains 26 times lower than the ray tracing model. Finally, a first version of a platform for the emulation of 5G systems has been developed on a game engine, which is the starting point for a complete 5G emulator. This platform not only contains the LIM model but also includes several 5G use cases in super realistic environments. The platform, which is based on the concept of "`Serious Game Engineering", breaks the limitations of mobile network simulators in terms of visualization capabilities and user interaction with network components in real time. / Inca Sánchez, SA. (2019). Serious Game Engineering and Lighting Models for the Realistic Emulation of 5G Systems [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/132695 / TESIS