ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NV / Systems using single carrier modulations for flight test transmissions perfectly fit noisy and time selective channels. However, the densification of the airport environment now makes the aero channel also frequency selective due to multiple reflections on surrounding buildings, especially while taxiing and taking off. Obviously, this has a direct consequence on hardware resources and user data rates. In such a context, COFDM represents an appealing solution thanks to its inherent robustness to multipath fading channels. But a direct application of an off-the-shelf COFDM standard is not straightforward as these standards are designed for specific channels whose characteristics are quite different from the aero one. That is why we made an experiment at Toulouse-Blagnac airport to jointly sound the channel and qualify a COFDM waveform. This paper then describes the construction of the waveform and the results of the channel sounding. From this, different standard paradigms are compared.

[pt] Este trabalho objetiva apresentar os resultados das medições e a análise da resposta do canal banda larga na faixa de frequências de 2.5 GHz em um ambiente urbano, através da técnica de sondagem de multiportadoras. Para isso, os perfis de retardo de potência desse canal foram obtidos com base nos dados medidos na região da Gávea na cidade do Rio de Janeiro, utilizando duas técnicas de limpeza de perfis de retardo. As técnicas de limpeza são apresentadas e seus resultados são comparados para a transmissão de um sinal de 20MHz de largura de banda. Os Retardos RMS (Root Mean Square) são calculados a partir desses Perfis de Retardo de Potências filtrados e o erro médio quadrático para cada técnica de limpeza é avaliado e comparado para algumas posições do receptor. / [en] This work presents the results of measurements and the analysis of the response of a wide band channel in the 2.5 GHz band for an urban environment, using the multicarrier sounding technique. To do this, the power delay profile (PDP) of the channel was obtained based on data measured at the neighborhood of Gávea, in the Rio de Janeiro, using two power delay profile filtering techniques. The power delay profile filtering techniques are presented and the results are compared for a transmitted signal of 20MHz bandwidth. The RMS (root mean square) delay spreads are determined from the filtered PDPs and from the original ones. The results are compared for some positions of the receiver and the quadratic mean error is evaluated.

Abstract The present dissertation deals with the evaluation of multiple-input multiple-output (MIMO) radio channel characteristics from time-division multiplexing (TDM)-switched MIMO channel sounding. The research can be divided into three main areas. First, the impacts of phase noise in TDM-switched MIMO channel sounding on channel capacity are studied. Second, we focus on those impacts on channel parameter estimation using the SAGE algorithm. And in the last part, spatial correlation, channel eigenvalue distribution, and ergodic capacity in realistic environments are analyzed. The rationale behind the first two areas is that most advanced MIMO radio channel sounders employ the TDM technique, which has significant problems from phase noise of the TX and RX phase locked loop (PLL) oscillators causing measurement errors in terms of estimated channel capacity and parameters. We propose statistical models that reproduce the capacity estimates. The effects of the sounding mode (SM), the length of pseudo-random noise (PN) sequence L of the sounding signal, and the system size are disclosed. The distinctive basis is to consider the impact of the actual phase noise in TDM switched MIMO channel sounding, instead of assuming white Gaussian-type phase noise. In a reality, the short-term phase noise component affecting one measurement cycle of a MIMO system plays an important role in the traditional estimators of the radio channel parameters and capacity. We show that the performance impairment is less than that been under the hypothesis of uncorrelated white Gaussian phase-noises samples. The difference is due to the non-vanishing correlation of phase-noise within the measurement cycle. Two approaches to mitigating the impact of phase noise are proposed. The former is the simple and efficient sliding averaging method, where the signal-to-noise ratio (SNR) of the channel impulse response can be increased. The latter is the choice of SM and L, which is more thorough. In the second part, two approaches to mitigating its impact on channel parameter estimation using the SAGE algorithm are also discussed. Besides the sliding averaging, which in general can increase the SNR, the new SAGE algorithm based channel parameter estimation based on the improved signal model accounting for the phase noise in the measurement device is proposed. Finally, the channel eigenvalue distribution and ergodic capacity based on complex hypergeometric functions and their asymptotic characteristics are analyzed. It is shown that the derived theoretical expressions closely approximate the simulated results of the measured finite-dimensional MIMO channels. The spatial correlation and the eigenvalue statistics in frequency selective channels for single and dual polarized antennas are investigated. This knowledge is useful when different MIMO and beamforming techniques are applied.

No description available.

Cette thèse résume trois années de travail dans le domaine de la caractérisation large bande du canal radio pour des applications projectiles. L’instrumentation des projectiles évolue avec la miniaturisation de l’électronique et l’accroissement constant de ses performances. L’échange de données par liaison sans fil bi-directionnelle entre le projectile et lastation de base doit s’effectuer aussi efficacement que possible. Afin de répondre à cette exigence, il est fondamental d’optimiser chaque élément de la chaîne de communication. Le canal, qui est le support où la propagation des ondes radio prend place, est l’un des éléments à modéliser.Dans le but de caractériser le canal radio pour ces applications, cette thèse a été structurée en cinq chapitres: dans les premier et deuxième chapitres, le contexte général de la thèse est présenté, introduisant le cadre de la thèse et donnant les éléments nécessaires pour comprendre le reste du manuscrit. Au chapitre trois, nous abordons le problème du développement des briques nécessaires pour caractériser le canal de propagation. Une des contributions de cette thèse est la définition d’un ensemble de procédures pour effectuer une modélisation de canal. Au chapitre quatre et cinq, nous présentons nos résultats. Alors qu’au chapitre quatre une étude préliminaire du canal est effectuée, une caractérisation complète est donnée au chapitre cinq. Les chapitres se terminent par la présentation d’un modèle de canal dédié aux simulations de communications numériques afin d’améliorer la liaison avec le projectile. Dans une dernière étape, les conclusions et les questions ouvertes sont détaillées. / This thesis summarizes three years of work in the field of wideband characterization of the radio channel in projectile applications. The popularization of the miniaturized electronics has allowed the instrumentation of projectiles. The information gathered by the onboard sensors needs to be sent from the projectile to the base station as efficiently as possible by means of bi-directional communication links. In order to fulfill this requirement, it is fundamental to optimize every element in the communication chain. The channel, which is the medium where the radio wave propagation takes places, is one of the elements to be modeled. With the purpose of characterizing the radio channel in projectile applications, this thesis has been structured in five chapters: in chapter one and two, the general context of the thesis is presented, introducing the reader to this topic and giving the necessary elements to understand the rest of the manuscript. In chapter three, we address the problem of developing the necessary elements in order to characterize the propagation channel. The first contribution of this thesis is found here in the form of a set of procedures to perform channel modeling. In chapter four and five, we present our results. While chapter in chapter four a preliminary study of the channel is performed, in chapter five a complete characterization is given. The chapters ends with the presentation of the second contribution of this thesis, i.e.a channel model to be used in simulations in order to improve the projectile communication link. In a last stage, the conclusions and open questions are detailed.

Cette thèse a apporté une contribution au défi de la caractérisation des canaux radios en bandes millimétriques ainsi que la validation d'un outil de simulation déterministe à travers un grand nombre de campagnes de mesures réalisées dans divers scénarios représentatives. Des questions de recherche liées à la caractérisation des canaux radio en bandes millimétriques et sa prédiction à travers un outil de simulation déterministe ont été abordées. Fournir des résultats précis et reproductibles est nécessaire dans le développement d'un système de communication. Ce défi peut être relevé en réalisant des campagnes de mesures qui capturent la réalité du canal de propagation constituant le point de départ. Dans cette thèse, les principales motivations scientifiques derrière ces campagnes de mesures étaient d'étudier la variabilité dans le temps et l'effet de l'environnement sur le canal de propagation dans les bandes millimétriques. Les bandes de fréquences adressées dans cette thèse sont identifiées comme étant importantes par l'UIT en vue d'un futur déploiement de la 5G à savoir 15, 28, 32 et 83 GHz. Les environnements considérés sont une conférence room, bureau, bibliothèque et micro-cellulaire. Les campagnes de mesures ont été menées en utilisant un sondage de canal fréquentiel avec l'utilisation d'un analyseur de réseau. L'exploitation des résultats de mesures ont permis d'apporter des éléments de réponses concernant le canal de propagation dans ces bandes de fréquences. D'autre part, les données de mesures ont été utilisés pour évaluer les performances et contribuer à la calibration d’un simulateur de canal radio à tracé de rayons (RT) reposant sur une approche déterministe. Le simulateur de canal déterministe utilisé dans cette thèse incorpore les mécanismes de propagation tels que le LOS, la réflexion et la diffraction. Le RT a permis de prédire le canal de propagation dans les bandes millimétriques avec une concordance acceptable avec les données de mesures. Ces résultats démontrent que le canal de propagation en bandes millimétriques a pour avantage d'être prédit avec de simple outil déterministe. / This thesis has contributed to the challenge of the radio channel characterizations in millimeter wave bands as well as the validation of a deterministic simulation tool through a large number of measurement campaigns carried out in various representative scenarios. Research questions related to the characterization of radio channels in millimetric bands and its prediction through a deterministic simulation tool were discussed. Providing accurate and repeatable results is necessary for the development of a communication system. This challenge can be meet by conducting measurement campaigns that capture the reality of the propagation channel and therefore constituting the starting point. In this thesis, the main scientific motivations behind these measurement campaigns were to study the time variability and the effect of the scattering environment of the propagation channel in the millimetric bands. The frequency bands addressed in this thesis are identified as important by the ITU for a future deployment of 5G, namely 15, 28, 32 and 83 GHz. The environments considered are a conference room, office, library and microcellular. The measurement campaigns were conducted using a frequency channel sounding technique with the use of a vector network analyzer. The exploitation of the measurement data provided some answers about the radio chennel propagation in these frequency bands. On the other hand, the measurements data were used to evaluate the performance and to contribute to the calibration of the ray-tracing tool (RT) based on a deterministic approach. The RT used in this thesis incorporates propagation mechanisms such as LOS, reflection and diffraction. The RT predicted the propagation channel in the millimeter bands with an acceptable level of agreement with respect to the measurement data. These results demonstrate that the propagation channel in millimetric bands has the advantage of being predicted with a simple deterministic tool.

This thesis describes fundamental approaches to quantify rate versus power consumption tradeoffs for cascaded communication systems. The discussion is bolstered by a large number of in-situ channel measurements, which are used in discussions of the power consumption of future massively broadband cellular systems. Chapter one provides an introduction. Chapter two discusses power consumption trends in modern communication systems. Chapter three introduces the consumption factor framework. Chapter four discusses the channel measurement campaign. Chapter five concludes the thesis, and uses the measurement results to estimate power consumption and capacity of future cellular systems. In addition, chapter five extends the consumption factor theory and draws fundamental conclusions about the energy price per bit for a general cascaded communication system. / text

Due to the advancement in technology and the increase in the amount of data beingtransferred through wireless channels, many developments in the techniques and speedof data transfer have been observed in the past few decades. The current trend incellular technology is transforming from 4G to 5G. So, to meet future requirements,it is highly necessary to have further improvements in technology like modulationtechniques, Channel access methods, etc. Many top research institutes around the worldare investing heavily in research and development of 5G.Radio waves have been used for a very long time in mobile phone communication,but providers are experimenting with broadcasting on millimeter waves which usehigher frequencies ranging from 6GHz to 300GHz. Data characteristics like power,SNR, interference, etc. need to be evaluated for these high frequencies. As 5G is still ininitial phases of development, there are not many testing tools to check and evaluateits performance. A testbed is a testing tool which is used for conducting rigorous,transparent, and replicable testing, experimenting and evaluating the performance ofthese propagated data at these high frequencies.The thesis work evaluates the implementation structures of the 5G testbed @15GHzand its performance in indoor and outdoor scenarios. It also talks about the methods ofsignal generation through Matlab and it’s transmission at 15GHz using Xilinx FPGAand Analog devices’ FMCOMMS5 transceiver. This data is then transmitted andreceived by patch antennas provided by Ericsson AB. Various techniques were used inorder to improve the signal, like using RF hardware components and software modules.Different channel sounding techniques were used in order to achieve the synchronizationbetween the transmitter and the receiver node in order to measure the properties ofthe channel. All of the experiments were performed by implementing a single-inputsingle-output system (SISO) module of the 5G testbed. This SISO system can be easilytransformed into a multiple-input-multiple-output system (MIMO) by replicating theoriginal SISO system.The result shares some interesting findings on the readiness of the 5G testbed for aiiiivbetter understanding of the future technology. It is concluded that this testbed providessomewhat a reliable platform to test the performance of the 5G technology. / Tack vare teknikutveckling och ökning i mängden data som sänds trådlöst, hardatatakterna ökat enormt under de senaste decennierna. Den senaste trended inomtrådlös kommunikationärövergången från 4G till 5G. För att möte framtida krav,finns det därför behov av ytterligare teknologiutveckling, t ex i modulationstekniker och kanalaccessmetoder. Många forskningsinstitut runt om i världen investerar därför i forskning och utveckling av 5G.Radiovågor har använts under väldigt lång tid för mobil kommunikation, men tillverkare och operatörer experimenterar med sändningar i millimetervågsområdet, som använder högre frekvenser i området från 6GHz till 300GHz. Egenskaper såsom effektdämpning, SNR, interferens, osv, behöver utvärderas för dessa högre frekvenser. Eftersom utvecklingen av 5G fortfarande är i en tidig fas, finns inte så många testverktygtillgängliga för prestandautvärdering. En testbädd är ett testverktyg som användsför att utföra rigorös, transparent och upprepningsbar testning, experimentering och prestandautvärdering av data som har sänts vid dessa höga frekvenser.Denna rapport utvärderar implementationsstrukturer för en 5G-testbädd vid 15GHz,och dess prestanda i inomoch utomhusscenarier. Den beskriver även metoder försignalgenerering via Matlab och sändning vid 15GHz mha Xilinx FPGA och Analog devices’ FMCOMMS5 radiomoduler. Signalen sänds sedan via patch-antenner från Ericsson AB. Olika metoder användes för att förbättra signalen, både med radiofrekvens hårdvara och mjukvarumoduler. Olika kanalmätningsmetoder har använts för att nå synkronisering mellan sändaroch mottagarnoderna, för att mäta kanalegenskaper. Alla experimenten utfördes genom att implementera en SISO-modul (en sändarresp. mottagarantenn) av 5G-testbädden. Detta SISO-system kan enkelt utökas till ett MIMO system (flera sändaroch mottagarantenner) genom att replikera SISO-systemet.Resultaten visar att 5G-testbädden är redo att användas för att nå bättre förståelse av framtida teknologin. Slutsatsen är att testbädden erbjuder en tämligen påliglig plattformför att utvärdera prestanda för 5G-teknologi.

Wideband measurements of the mobile-to-mobile channel, especially of the harshest channels, are necessary for proper design and certification testing of mobile-to-mobile communications systems. A complete measurement implies that the Doppler and delay characteristics are measured jointly. However, such measurements have not previously been published. The main objective of the proposed research is to develop channel models for specific scenarios from data obtained in a wideband mobile-to-mobile measurement campaign in the 5.9 GHz frequency band. For this purpose we developed a channel sounding system including a novel combined waveform. In order to quantify and qualify either the recorded channel or the proposed generated channel, we developed a simulation test-bed that includes all the characteristics of the proposed digital short range communications (DSRC) standard. The resulting channel models needed to comply with the specifications required by hardware channel emulators or software channel simulators. From the obtained models, we selected one to be included in the IEEE 802.11p standard certification test. To further aid in the development of software radio based receivers, we also developed an orthogonal frequency division multiplexing (OFDM) synchronization algorithm to analyze and compensate synchronization errors produced by inaccessible system clocks.

The continuous advancement in wireless communications technology demands new approaches to improving the capacity of existing radio links. The high data throughput required can be achieved by the complete utilization of space, time and polarization diversities inherent in any propagation environment. Among the different propagation scenarios, the indoor channels represent a particularly challenging problem given the number and complexity of interactions between the transmitted signal and the environment. This dissertation explores the interrelation between propagation physics and space-time-polarization diversity based on a novel high resolution channel sounding and reconstruction technique. First, a method to reconstruct the indoor complex channel response based on a limited set of samples and the elimination of the interference using deconvolution techniques is presented. Then, the results for the joint angle-of-arrival, delay characterization and depolarization of electromagnetic waves are presented. Finally, a novel approach to using depolarized multipath signals to boost the receiver signal-to-noise performance is presented. The current study shows that full utilization of the diversities of channel novel wireless systems can be proposed with significant improvement in capacity.