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1

Qasim, Muhammad, e Ali Chaudhry Majid. "Signal Processing on Ambric Processor Array : Baseband processing in radio base stations". Thesis, Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-1660.

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The advanced signal processing systems of today require extreme data throughput and low power consumption. The only way to accomplish this is to use parallel processor architecture.

The aim of this thesis was to evaluate the use of parallel processor architecture in baseband signal processing. This has been done by implementing three demanding algorithms in LTE on Ambric Am2000 family Massively Parallel Processor Array (MPPA). The Ambric chip is evaluated in terms of computational performance, efficiency of the development tools, algorithm and I/O mapping.

Implementations of Matrix Multiplication, FFT and Block Interleaver were performed. The implementation of algorithms shows that high level of parallelism can be achieved in MPPA especially on complex algorithms like FFT and Matrix multiplication. Different mappings of the algorithms are compared to see which best fit the architecture.

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2

Chaufray, Jean-Marie. "Détection et démodulation de stations de base dans le réseau UMTS". Marne-la-Vallée, 2003. http://www.theses.fr/2003MARN0161.

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Cette thèse qui s’est déroulée dans le cadre d’un contrat CIFRE entre Thales Communications et l’Université de Marne-la-Vallée s’inscrit dans le contexte d’un projet européen. Les travaux effectués concernent la détection et la démodulation de stations de base d’un réseau UMTS-FDD, à l’aide d’une antenne munie de plusieurs capteurs. Dans une première partie, nous avons développé et testé une procédure pour la détection et la synchronisation des stations de base basée sur des algorithmes exploitant les dimensions spatiale et temporelle des signaux reçus. La deuxième partie est consacrée à l’estimation du canal de propagation. Nous avons développé un estimateur des statistiques du second ordre du canal de propagation et nous l’avons appliqué à l’amélioration de l’estimateur de canal classique. Enfin, dans la troisième partie, après avoir présenté plusieurs structures de démodulation, nous avons évalué leurs performances asymptotiques théoriques et nous les avons comparées par des simulations dans un environnement réaliste
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3

Gollbo, Simon, e Adam Sköld. "Base stations for communication in obstructed environments". Thesis, Uppsala universitet, Signaler och System, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-255243.

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The purpose of this project was to produce signal relay stations that could receive information via 2.4 GHz radio and relay the information to a designated target station. If a relay station was located outside of signal range for the target station it was supposed to utilize other relay stations to transfer the information to the target station, so called multi-hop. The would-be application of the relay stations was orienteering. When an orienteer punches a checkpoint the signal stations would relay information of who punched the control, when it was punched and the checkpoint that was punched to the speaker tower in the goal area. The work resulted in prototypes which fulfilled the statement of purpose and was tested at an orienteering competition with satisfactory results. The performance of the prototypes was tested and found adequate for the would-be application.
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4

Law, Eugene. "TECHNIQUE FOR DETERMINING THE POWER FLUX DENSITY OF INTERFERING SIGNALS AT TELEMETRY RECEIVING STATIONS". International Foundation for Telemetering, 2005. http://hdl.handle.net/10150/604814.

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ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada
This paper will present techniques for accurately measuring the power flux density (PFD) of interfering signals at telemetry receiving stations. The solar power flux density is measured daily by radio astronomers and will be used as a calibration signal. The electromagnetic spectrum is being used more intensely as time marches on so being familiar with interference measurement techniques is becoming more important because more interfering signals are present.
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5

ERTUNCAY, DENIZ. "Temporal and spatial analysis of near fault stations in terms of impulsive behavior". Doctoral thesis, Università degli Studi di Trieste, 2020. http://hdl.handle.net/11368/2961198.

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Increasing number of seismic stations located in close proximity to active faults allows analysis of seismic signals that are recorded in near fault regions. Unique seismic signals, called “impulsive” or “pulse shaped” signals, are captured in velocity waveforms in numerous large magnitude earthquakes. In such waveforms, the earthquake is recorded as a one or several long period high amplitude signals. Long period signals are important in engineering seismology due to their large loads on structures. Ground motion prediction equations and design codes fail to capture the amplitudes in long periods of the impulsive signals. In this thesis nature of impulsive signals and their spatial distribution in near fault regions are investigated. To do that two different algorithm are developed in order to distinguish impulsive signals from non-impulsive signals. Moreover, the probability of the pulse shaped signal occurrence is estimated. In order to investigate the impulsive signals, near fault records from major crustal earthquakes are merged into a dataset. It contains waveforms that are coming from well known seismogenic zones. Waveforms in the dataset are also analyzed by implementing several previous studies to make comparison. The first pulse shaped signal classification algorithm is developed using wavelet analysis. Wavelet analysis decomposes the signal into time-frequency domain which provides the energy variation with time and frequency. The wavelet power spectrum of velocity waveforms are analyzed by using Ricker and Morlet wavelets. A threshold of minimum amplitude is applied. A comparison is made between the total energy of a signal and the energy of the time incidence where peak ground velocity is measured. Furthermore time incidence where maximum spectral energy is located in time is also taken into consideration. Energy ratios are used for determination of impulsive signals. It is found that a Ricker wavelet explains the features of the impulsive part of the velocity waveforms more accurately than the Morlet wavelet. It can measure the period of the pulse and the phase shift of the impulsive parts of the waveform. Spectral features of the impulsive signals are also captured successfully using a Ricker wavelet. The second classification algorithm uses convolutional neural networks. In order to train the convolutional neural networks, synthetic impulsive signals are created. A model is developed using real non-impulsive velocity waveforms from the dataset and synthetic impulsive waveforms. Impulsive signals are manually labeled as impulsive or non-impulsive. The trained model is run on the real manually picked impulsive signals of the dataset and the performance of the convolutional neural network, the wavelet method and various previously published methods are benchmarked. The convolutional neural networks approach correctly identifies almost 97% of the impulsive signals. Accuracy rate of the model is superior than other models. In order to understand the probability of the impulsive signals on earthquakes, a multi-variate Bayes classifier method is implemented on the dataset. Various information about the fault, earthquake and station are analyzed and 3 parameters that are correlated with the impulsive signals are used for the probability calculations. Probability models are developed for normal, reverse and strike slip faults. The validity of this model is tested on the data set. Developed models can provide pulse probability distributions without requiring earthquake-specific parameters. A relation between the period of the pulses and the moment magnitude is also developed.
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6

Ghorabi, Moncef. "Vitesses de groupe mesurée en deux stations du réseau GEOSCOPE et régionalisation de la structure globale du manteau supérieur". Paris 7, 1985. http://www.theses.fr/1985PA07F056.

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Analyse des données du mode fondamental des ondes de Love et de Rayleigh, obtenues aux deux premières stations du réseau, SSB et PCR, pendant les années 1982 à 1984. Calcul des courbes de dispersion en vitesse de groupe sur les trajets directs et inverses et quelques trains d'ordre supérieur, pour les séismes suffisammant forts enregistrés dans ces stations durant cette période. Discussion qualitative des courbes obtenues regroupées par azimuts et distances épicentrales proches par rapport à chacune des stations; influence des structures tectoniques traversées
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7

Wagner, Dörte [Verfasser], e Hans Von [Akademischer Betreuer] Storch. "Evaluation of Storminess by Early 20th Century Atmospheric Data from Signal Stations along the German Coastline / Dörte Wagner ; Betreuer: Hans von Storch". Hamburg : Staats- und Universitätsbibliothek Hamburg, 2017. http://d-nb.info/1147968993/34.

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8

Sundberg, Simon. "Localization of eNodeBs with a Large Set of Measurements from Train Routers". Thesis, Karlstads universitet, Institutionen för matematik och datavetenskap (from 2013), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-75456.

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This master thesis investigates the possibility of locating LTE base stations, known as eNodeBs, using signal measurements collected by routers on trains. Four existing algorithms for transmitter localization are adopted: the centroid, strongest signal, Monte Carlo path loss simulation and power difference of arrival (PDoA) methods. An improved version of Monte Carlo path loss simulation called logloss fitting is proposed. Furthermore, a novel localization method called sector fitting is presented, which operates solely on the cell identity and geographical distribution of the measurements. The methods are evaluated for a set of manually located eNodeBs, and the results are compared to other external systems that can be used to locate eNodeBs. It is found that the novel sector fitting algorithm is able to considerably improve the accuracy of the logloss fitting and PDoA methods, but weighted centroid is overall the most accurate of the considered methods, providing a median error of approximately 1 km. The Google Geolocation API and Mozilla Location Service still provides estimates that are generally closer to the true location than any of the considered methods. However, for a subset of eNodeBs where measurements from all sectors are available, the novel sector fitting algorithm combined with logloss fitting outperforms the external systems. Therefore, a hybrid approach is suggested, where sector fitting combined with logloss fitting or weighted centroid is used to locate eNodeBs that have measurements from all sectors, while Google Geolocation API or Mozilla Location Service is used to locate the remaining eNodeBs. It is concluded that while the localization performance for those eNodeBs that have measurements from all sectors is relatively good, further improvements to the overall results can likely be obtained in future work by considering environmental factors, the angular losses introduced by directional antennas, and the effects of downlink power control.
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9

Pelcat, Maxime. "Prototypage Rapide et Génération de Code pour DSP Multi-Coeurs Appliqués à la Couche Physique des Stations de Base 3GPP LTE". Phd thesis, INSA de Rennes, 2010. http://tel.archives-ouvertes.fr/tel-00578043.

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Le standard 3GPP LTE (Long Term Evolution) est un nouveau standard de télécommunication terrestre dont la couche physique des stations de base, appelées eNodeB, est particulièrement coûteuse. Les processeurs de traitement du signal (DSP) sont largement employés dans les stations de base pour calculer les algorithmes de la couche physique. Les DSPs de dernière génération sont des systèmes complexes et hétérogènes. Il n'existe pas actuellement de solution idéale pour distribuer les parties d'une application comme le LTE sur les différents cœurs contenus dans un eNodeB. Dans cette thèse, nous présentons une méthode de travail pour le prototypage rapide et la génération de code automatique. Certains algorithmes de la couche physique du LTE étant trop variables pour une distribution hors-ligne, nous présentons un distributeur adaptatif capable de faire des choix en temps réel sur la base de temps d'exécution prédits.
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10

Sun, Zhibin. "Application of artificial neural networks in early detection of Mastitis from improved data collected on-line by robotic milking stations". Lincoln University, 2008. http://hdl.handle.net/10182/665.

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Two types of artificial neural networks, Multilayer Perceptron (MLP) and Self-organizing Feature Map (SOM), were employed to detect mastitis for robotic milking stations using the preprocessed data relating to the electrical conductivity and milk yield. The SOM was developed to classify the health status into three categories: healthy, moderately ill and severely ill. The clustering results were successfully evaluated and validated by using statistical techniques such as K-means clustering, ANOVA and Least Significant Difference. The result shows that the SOM could be used in the robotic milking stations as a detection model for mastitis. For developing MLP models, a new mastitis definition based on higher EC and lower quarter yield was created and Principle Components Analysis technique was adopted for addressing the problem of multi-colinearity existed in the data. Four MLPs with four combined datasets were developed and the results manifested that the PCA-based MLP model is superior to other non-PCA-based models in many respects such as less complexity, higher predictive accuracy. The overall correct classification rate (CCR), sensitivity and specificity of the model was 90.74 %, 86.90 and 91.36, respectively. We conclude that the PCA-based model developed here can improve the accuracy of prediction of mastitis by robotic milking stations.
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11

Runyon, Ginger R. "Parallel processor architecture for a digital beacon receiver". Thesis, Virginia Tech, 1990. http://hdl.handle.net/10919/41422.

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12

Paillier, Laurie. "Architecture de récepteur cohérent pour les liens optiques satellite-sol avec optique adaptative". Electronic Thesis or Diss., Institut polytechnique de Paris, 2020. http://www.theses.fr/2020IPPAT026.

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L’émergence et la multiplication de moyens d’observation du sol de résolution croissante et de réseaux de télécommunication spatiaux à très haut débit pour l’internet globalisé rendent nécessaire d’accroître la capacité de transmission de données entre l’espace et le sol de plusieurs ordres de grandeur. Les liens optiques, avec des débits de plusieurs dizaines de Gbps par canal, constituent une solution à très fort potentiel si les techniques de modulation de phase exploitées dans les réseaux fibrés peuvent y être appliquées. L’enjeu de cette thèse est d’investiguer le recours à des méthodes de modulation de phase pour des liens optiques satellite-sol en prenant en compte les spécificités propres à l’application : bruits de phase des lasers, effet Doppler, et impact de la propagation à travers l’atmosphère turbulente corrigé par optique adaptative pour maximiser l’efficacité de la détection cohérente. Dans ce but, j’ai développé un outil de simulation complète d’une transmission cohérente BPSK incluant les étapes de propagation à travers l’atmosphère, de détection et de démodulation. En s’appuyant sur cet outil, nous avons proposé deux architectures de récepteur numérique : l’une exploitant une boucle à verrouillage de phase, l’autre reposant sur une synchronisation en boucle ouverte. La méthodologie de conception développée à cette occasion permet de réduire l’impact du bruit de phase des lasers sur la précision de synchronisation, ce terme restant néanmoins prépondérant. L’étude menée montre que les deux architectures présentent des performances comparables en termes de précision de synchronisation, de seuil de convergence et de taux d’erreur dans différentes conditions de turbulence. Les performances en taux d’erreur obtenues soulignent l’importance de la qualité de la correction par optique adaptative. Une confirmation par modélisation du faible impact du bruit de phase turbulent sur la performance est apportée. Ces travaux laissent envisager la possibilité d’un accroissement très significatif du débit atteignable pour des liens de télémesure cohérents dans le cas de l’emploi de constellations d’ordre supérieur (QPSK et au-delà) au prix d’une correction par optique adaptative de bonne qualité
Both the increasing imaging resolution of earth observation satellites and the advent of a space-based globalized internet are currently urging for very high data rate transmissions between space and ground.With the promise to provide tens of Gbps per channel, optical links may become a major breakthrough technology, assuming that the technological assets developed for the fibered networks can be exploited. Especially, phase modulation techniques have demonstrated their tremendous efficiency for fibered networks. The aim of this thesis was to investigate the feasibility of their transposition to the case of satellite-to-ground optical links, accounting for their specificities: laser phase noise, Doppler effect, and the impact of propagation through the turbulent atmosphere and its correction by adaptive optics to maximize coherent detection efficiency. To investigate the main limitations of such a BPSK modulated coherent link, I developed a tool performing a detailed simulation of the data transmission process. It includes the beam propagation through the atmosphere, the atmospheric disturbances correction by adaptive optics, and the synchronization step necessary to recover the modulated phase. We investigated two architectures of digital receiver: one based on a phase-locked loop, and the other one based an open loop approach. We formalized a design methodology to reduce the impact of laser phase noise on the accuracy of synchronization. Laser phase noise remains however the main contributor to the residual phase error. The two architectures achieve comparable performance in terms of residual phase error, convergence threshold and error rate. The impact of atmospheric turbulence and its correction by adaptive optics was investigated for different turbulence conditions. As expected, the importance of the quality of the adaptive optics correction is highlighted. We confirm by modeling the limited impact of turbulent phase noise on the performance.This work opens prospects for a strong increase in the achievable bit rate for coherent telemetry links when using higher-order constellations (QPSK and beyond)
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13

Bosse, Jonathan. "Géolocalisation de sources radio-électriques : stratégies, algorithmes et performances". Phd thesis, École normale supérieure de Cachan - ENS Cachan, 2012. http://tel.archives-ouvertes.fr/tel-00700670.

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Cette thèse porte sur la géolocalisation de sources radio-électriques dans le cadre du traitement d'antenne, c'est-à-dire l'estimation de la position, dans le plan ou l'espace, de sources incidentes à divers réseaux multicapteurs (stations de base). Il s'agit de concevoir des algorithmes estimant au mieux la position d'un ensemble de sources et de caractériser les limites théoriques, en termes d'erreur quadratique moyenne, des approches envisagées pour résoudre le problème de géolocalisation. Nous nous plaçons dans un contexte passif, sans a priori sur les signaux émis. De manière classique, la position des sources est souvent estimée à l'aide de paramètres intermédiaires (angles d'arrivée, temps d'arrivée, fréquences d'arrivée ...) estimés localement sur chacune des stations de base dans un premier temps. Ces paramètres intermédiaires sont ensuite transmis à une unité centrale de traitement qui réalise l'étape de localisation dans un second temps. On parle parfois d'approche en deux étapes. Cette solution décentralisée est par nature sous-optimale. Une approche optimale du problème de localisation consiste à estimer directement la position des sources à l'aide de l'ensemble des signaux reçus par les stations et transmis directement à l'unité centrale de traitement. Il convient alors de réaliser la localisation à l'aide d'une approche centralisée ne comportant qu'une seule étape : la position des sources étant directement estimée à partir de l'ensemble des signaux disponibles à l'unité centrale de traitement. Le problème à résoudre dépend directement de la position des sources et non plus de paramètres intermédiaires. Cette approche du problème de localisation offre de nouvelles perspectives quant à la conception de nouveaux algorithmes et pose la question de son intérêt théorique en termes d'amélioration des performances de localisation. Dans cette thèse, nous examinons l'intérêt constitué par l'exploitation simultanée des signaux de toutes les stations de base afin de réaliser la localisation. Nous nous attachons dans un premier temps à caractériser en termes d'erreur quadratique moyenne et de borne de Cramer-Rao les approches centralisées et décentralisées pour la localisation dans un contexte de signaux bande étroite sur l'ensemble du réseau de stations. Ensuite, pour le cas plus général de signaux large bande sur l'ensemble du réseau de stations, nous proposons une approche basée sur un traitement spatio-temporel. Nous montrons son intérêt comparativement à l'état de l'art et aux performances optimales théoriques qui font elles-mêmes l'objet d'une partie des travaux exposés dans cette thèse. Un algorithme de géolocalisation en contexte de multitrajets est également proposé dans cette thèse.
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14

Kaiser, Julius A., e Fredrick W. Herold. "AUTONOMOUS GROUND STATION FOR SATELLITE COMMUNICATIONS". International Foundation for Telemetering, 1999. http://hdl.handle.net/10150/607306.

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International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada
Employment of the retro-directive technique described in Reference 1 describes a totally Autonomous Ground Station providing hemispheric coverage and continuous tracking. This System establishes communications between the satellite and ground station without human intervention or moving parts. When a satellite is in view, the ground station beacon antenna, using CDMA, enables the desired satellite transmitter and directs its beam to the ground station. The ground station, using the satellite’s transmitted signal, directs it’s receive and transmit arrays to point the ground station beams to the satellite, establishing two-way communications. The process is automatic and provides continuous horizon to horizon tracking.
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15

Crook, Alex, e Gregory Kissinger. "Using COTS Graphics Processing Units in Signal Analysis Workstations". International Foundation for Telemetering, 2011. http://hdl.handle.net/10150/595798.

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ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada
Commercial off-the-shelf (COTS) graphics processing units (GPU) perform the signal processing operations needed for video games and similar consumer applications. The high volume and competitive nature of that industry have produced inexpensive GPUs with impressive amounts of signal processing power. These devices use parallel processing architectures to execute DSP algorithms far faster than single, or even multi-core central processing units typically found in workstations. This paper describes a project which improves the performance of a radar telemetry application using the NVidia™ brand GPU and CUDA™ software, although the results could be extended to other devices.
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16

DECHELLE, FRANCOIS. "Definition d'une station de developpement pour des applications de traitement du signal sur multi-processeurs". Paris 6, 1989. http://www.theses.fr/1989PA066585.

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Les methodes actuelles de programmation dans le domaine des systemes temps reel de traitement du signal conduisent a des temps de developpement tres longs et a des couts penalisants dans un contexte industriel. Une methode de programmation est proposee, visant a accelerer le passage de la specification de l'application a son execution temps reel sur un reseau de processeurs de traitement du signal. Elle repose sur l'utilisation d'un langage flots de donnees et temps reel synchrone, signal. Les differentes etapes de cette methode sont detaillees: specification de l'application et simulation fonctionnelle, repartition, mise en uvre sur une architecture multi-processeurs. Une architecture materielle et logicielle a ete definie et realisee a fin d'experimentation. Elle est construite autour du processeur de traitement du signal ts68930 (thomson semiconducteurs et trt). Ses differents elements sont decrits: architecture multi-processeurs, systeme temps reel, interface utilisateur
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17

Hargis, Brent H. "Analysis of Long-Term Utah Temperature Trends Using Hilbert-Haung Transforms". BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/5490.

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We analyzed long-term temperature trends in Utah using a relatively new signal processing method called Empirical Mode Decomposition (EMD). We evaluated the available weather records in Utah and selected 52 stations, which had records longer than 60 years, for analysis. We analyzed daily temperature data, both minimum and maximums, using the EMD method that decomposes non-stationary data (data with a trend) into periodic components and the underlying trend. Most decomposition algorithms require stationary data (no trend) with constant periods and temperature data do not meet these constraints. In addition to identifying the long-term trend, we also identified other periodic processes in the data. While the immediate goal of this research is to characterize long-term temperature trends and identify periodic processes and anomalies, these techniques can be applied to any time series data to characterize trends and identify anomalies. For example, this approach could be used to evaluate flow data in a river to separate the effects of dams or other regulatory structures from natural flow or to look at other water quality data over time to characterize the underlying trends and identify anomalies, and also identify periodic fluctuations in the data. If these periodic fluctuations can be associated with physical processes, the causes or drivers might be discovered helping to better understand the system. We used EMD to separate and analyze long-term temperature trends. This provides awareness and support to better evaluate the extremities of climate change. Using these methods we will be able to define many new aspects of nonlinear and nonstationary data. This research was successful and identified several areas in which it could be extended including data reconstruction for time periods missing data. This analysis tool can be applied to various other time series records.
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18

Al, Hasan Mohammad Sami. "Role of non-signage elements in the image of underground stations a study of Hong Kong MTR users' cognitive image /". Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B42931514.

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Mohammed, Taqhiuddin. "Designing an Emergency Traffic Signal System (ETSS): A Case Study of an Intersection Along U.S.1, Fairfax County, Virginia". Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/33411.

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Access to highways from a local firehouse is a major problem for emergency services. Motorists often do not see flashing lights or hear sirens from the approaching emergency vehicles (EV) until emergency vehicles reach the highway entrance, often too late to take appropriate action. Many locations have installed special signals called emergency traffic signal systems (ETSS) or used signal preemption to notify motorists and to stop traffic to allow the emergency vehicle to enter the highway safely. This thesis will examine the effectiveness of one such installation at the intersection along U.S.1 at Beedo Street and some of the impacts it has on highway traffic. The evaluation of the said installation is carried out in terms of delay to EV; conflict potential between EV and other vehicles and response of the motorists to the ETSS. This thesis also proposes two alternative designs of ETSS to improve the existing signal system.
Master of Science
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Koksal, Murat Miran. "Positioning Based On Tracking Of Signal Parameters In A Single Base Station Wimax Network Using Fingerprinting". Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612248/index.pdf.

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IEEE 802.16 is a point to multipoint broadband wireless access standard, designed from ground up for fast and reliable mobile networking. Several location-related MAC layer fields specified in the standard indicate that WiMAX networks can be convenient backbones for future positioning systems. Information encapsulated in MAC headers is especially important for single base station positioning systems which require fewer network resources than multiple reference station location systems, but need more location-related input data. In this thesis, an algorithm for positioning mobile stations in a single base station network is presented to investigate location capability of WiMAX systems. The algorithm makes use of fingerprinting to create a training database and seeks to find locations of mobile stations by tracking them according to their signal parameters. Experimental results give an idea about how a single base station positioning system performs in the absence of sufficient location-related data, and suggest that better results can be obtained if MAC headers specified in IEEE 802.16 standard can be accessed.
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Pasinetti, Nadia. "Wound healing signals mediated by Rho/ROCK activation in response to radiotherapy and consequences fot treatmeny of late damage within normal tissues". Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00714360.

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Radiotherapy is the second most important treatment modality after surgery in the treatment of cancer. Recent technical advancements, such as intensity-modulated radiation therapy (IMRT) or image-guided radiation therapy (IGRT), combined with new targeted drugs have significant promise for therapeutic outcome. However radiation treatment could result in disabling normal tissue injury and in the development of progressive fibrosis in a subset of sensitive patients and in long-term cancer survivors. The main feature of tissue fibrosis is excessive accumulation of abnormal and cross-linked collagen mainly composed of fibrillar and immature extracellular matrix (ECM) components.The organs that can be affected by this phenomenon are liver, skin, intestine, kidneys and lungs. From a clinical point of view, fibrosis can be seen as an irreversible condition, without solution. We and others recently showed that beside the activation of the canonical TGF-β/Smad pathway, other intracellular signaling cascades including the Rho/ROCK pathway are switched on in fibrotic tissues. Interestingly, the Rho/ROCK pathway seems differentially activated in radiation-induced intestinal fibrosis, thereby providing a rationale for a specific, targeted anti-fibrotic strategy. Pharmacological inhibition of Rho using statins indeed prevent and even reverse intestinal radiation fibrosis.In our studies, we showed the role of Statin (Pravastatin e Simvastatin) and a specific inhibitor ROCK inhibitors (Y-27632) in a mice model of pulmonary induced-fibrosis obtained by a pharmacological approach (Bleomycin - BLM). Indeed, we developed a model of lung fibrosis by complete irradiation of chest and tested Pravastatin action. Confirmation of the involvement of Rho/ROCK/CTGF pathway in lung fibrosis are shown by immunohistochemistry: Pravastatin-treament normalized the expression of three markers: RhoB, TGF-RII and CTGF.Then, in models of radiation induced gut and lung fibrosis, we analysed, from a immunohistological point of view, the underlying mechanisms of the antifibrotic action of Pravastatin via MMP2-TIMP2 axis. Interestingly we found a different impact on fibrolysis when Pravastatin was administered preventively or curatively.Finally, in vitro, we investigate by zymography the expression of Gelatinases (MMP2 and MMP9) in primary lung fibroblasts cultures exposure at the different radiation and Pravastatin doses. Metalloproteases would appear to be in turn involved in pro-fibrolytic mechanisms induced by statin.The multiplicity of actors involved in the pathogenesis of fibrotic lesions explains why the definition of an effective therapeutic strategy is so complex.Researches in mechanistic processes of normal tissue damage paved the way for new therapeutic approaches. These new targets include reduction of vascular activation, inflammation and thrombosis and new molecular targets definition. Effective strategies are multiple on preclinical models, but numerous efforts have to be made to achieve the complicated goal of protection of normal tissues from the side effects of radiation therapy.
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22

Xiao, Mingxiang, e 肖明祥. "Quadrature predistortion using difference-frequency technique forbase-station high-power amplifiers". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B43223953.

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Xiao, Mingxiang. "Quadrature predistortion using difference-frequency technique for base-station high-power amplifiers". Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43223953.

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RICHARD, JOEL. "Application de methodes de traitements numeriques de signaux a la detection, compression et reconnaissance d'evenements d'origines sismiques dans une station autonome de type sismographe fond de mer". Rennes 1, 1988. http://www.theses.fr/1988REN10121.

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Les conditions de fonctionnement des sismographes fond de mer imposent le conditionnement des signaux pour limiter les debits d'information lors de l'enregistrement ou de la transmission. Trois methodes deduites de la transformation de fourier, de la transformation de walsh et de la modelisation autoregression sont examines et testes
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25

Chalermwisutkul, Suramate. "Large signal modeling of GaN HEMTs for UMTS base station power amplifier design taking into account memory effects". [S.l.] : [s.n.], 2007. http://deposit.ddb.de/cgi-bin/dokserv?idn=984082980.

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26

Al, Hasan Mohammad Sami. "Role of non-signage elements in the image of underground stations: a study of Hong Kong MTR users' cognitiveimage". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B42931514.

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27

Poussielgue, Nicolas. "Signal acoustique et activité thermique dans les lacs de cratère de volcans actifs. Réalisation d'une station de mesure hydroacoustique au Taal (Philippines)". Phd thesis, Chambéry, 1998. http://tel.archives-ouvertes.fr/tel-00811782.

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Afin d'étudier les variations temporelles du signal acoustique dans un lac de cratère nous avons réalisé une station de mesure permanente et l'avons installée en novembre 1994 dans le lac de cratère du volcan Taal (philippines). Cette station acquiert tous les quarts d'heure des échantillons temporels du signal acoustique (à 40 mètres de profondeur) dans trois bandes de fréquences différentes: BF(<500hz), MF (<12,5 kHz) et HF(<500kHz). Le traitement des données permet la représentation d'un sonogramme. Une variation importante du signal acoustique a été induite par le séisme de Mindoro (magnitude 7. 1 ) du 15 Novembre 1994 situé à 46 km du Taal. La puissance thermique apportée au lac chute brutalement de 50%, le débit gazeux est ralenti de 1/10° . Les flux liquide et gazeux ne reviennent à leur état initial que 5 jours après. On assiste à un phénomène transitoire qui touche tous les paramètres mesurés : déformations, acoustique, thermique. A partir des données de la température du lac de cratère du Taal et des valeurs météorologiques, un calcul de l'apport énergétique de l'édifice volcanique au lac de cratère de 1990 à 1995 permet de mettre en évidence la reprise d'activité du volcan Taal depuis 1990, la puissance thermique mesurée passant de 50MW à 250MW. Le flux gazeux mesuré ne suffisant pas pour apporter une telle puissance, que ce soit au TaaI ou au Ruapehu, nous concluons que la chaleur est apportée majoritairement par des échanges liquides. Nous montrons par ailleurs que les variations de l'inclinaison du volcan sont fortement corrélées avec les variations de la puissance thermique. La mesure du signal acoustique en milieu volcanique est donc une méthode prometteuse qui mérite d'être mise en oeuvre dans d'autres édifices volcaniques.
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28

Толбатов, Володимир Аронович, Владимир Аронович Толбатов, Volodymyr Aronovych Tolbatov, Г. І. Войченко, А. В. Толбатов, О. Б. В'юненко e І. О. Жижеріна. "Забезпечення захисту сигналу FM радіостанції зі стерео кодуванням у режимі pilot-tone". Thesis, Сумський державний університет, 2017. http://essuir.sumdu.edu.ua/handle/123456789/65165.

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29

Wang, Willy. "Evaluating the use of PXI modules in tests of a radio base station". Thesis, KTH, Radio Systems Laboratory (RS Lab), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-143810.

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This thesis project was carried out at the electromagnetic compatibility (EMC) department at Ericsson AB. One of the department’s goals is to seek a possible replacement to the box test instruments by utilizing PCI extension for instrumentation (PXI) modules. The main objective of this project is to evaluate how different PXI modules work during testing of a radio base station (RBS), in terms of performance, test time, and cost. A downlink decoder was implemented in LabVIEW with an extension called MathScript and several software test solutions were examined to measure error vector magnitude (EVM), frequency error, and power, and to perform parallel measurements in a multiple radio access technology (multi-RAT) test configuration. Moreover, several uplink tests were performed to decide if PXI modules are a suitable substitute for the previous box based test instruments. The findings from this study show that PXI modules can replace the previous box based test instruments. However it was concluded that not all areas can be covered and not all discrete test instrument can (yet) be replaced. Future work should complete the downlink decoder implementation in the field programmable gate array (FPGA) level in order to further improve the performance further. Future work should also examine if it is possible to replace all of the discrete test instruments with PXI modules.
Detta examensarbete utfördes på elektromagnetisk kompatibilitet (EMC) avdelningen på Ericsson AB. Ett utav avdelningens mål är att hitta en möjlig ersättare till de tidigare boxbaserade testinstrumenten genom PCI extension for instrumentation (PXI) moduler. Huvudmålet i detta projekt är att utvärdera hur olika PXI-moduler fungerar i basstationstester med hänsyn till prestanda, testtid och kostnad. En avkodare i nerlänk har implementerats i LabVIEW med hjälp av MathScript och flera mjukvarutestlösningar har undersökts för att mäta error vector magnitude (EVM), frekvensfel och effekt, samt att utföra parallella mätningar i en multipel radioteknik (multi-RAT) testkonfiguration. Dessutom har flera upplänkstester utförts för att avgöra om PXI-moduler är en lämplig ersättare till de tidigare boxbaserade testinstrumenten. Resultaten från denna studie visar att PXI-moduler kan ersätta tidigare boxbaserade testinstrumenten, men dessa resultat visar även att inte alla områden kan täckas och inte alla diskreta testinstrument kan ersättas (ännu). Framtida arbete ska slutföra implementationen av avkodare i nerlänk i fältprogrammerbar grindmatris (FPGA)-nivå för att förbättra prestandan ytterligare. Framtida arbete bör även undersöka om det är möjligt att ersätta alla diskreta testinstrument med PXI-moduler.
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30

Mollén, Christopher. "High-End Performance with Low-End Hardware : Analysis of Massive MIMO Base Station Transceivers". Doctoral thesis, Linköpings universitet, Kommunikationssystem, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-143455.

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Massive MIMO (multiple-input–multiple-output) is a multi-antenna technology for cellular wireless communication, where the base station uses a large number of individually controllable antennas to multiplex users spatially.  This technology can provide a high spectral efficiency.  One of its main challenges is the immense hardware complexity and cost of all the radio chains in the base station.  To make massive MIMO commercially viable, inexpensive, low-complexity hardware with low linearity has to be used, which inherently leads to more signal distortion.  This thesis investigates how the degenerated linearity of some of the main components—power amplifiers, analog-to-digital converters (ADCs) and low-noise amplifiers—affects the performance of the system, with respect to data rate, power consumption and out-of-band radiation. The main results are: Spatial processing can reduce PAR (peak-to-average ratio) of the transmit signals in the downlink to as low as 0B; this, however, does not necessarily reduce power consumption.  In environments with isotropic fading, one-bit ADCs lead to a reduction in effective signal-to-interference-and-noise ratio (SINR) of 4dB in the uplink and four-bit ADCs give a performance close to that of an unquantized system.  An analytical expression for the radiation pattern of the distortion from nonlinear power amplifiers is derived.  It shows how the distortion is beamformed to some extent, that its gain never is greater than that of the desired signal, and that the gain of the distortion is reduced with a higher number of served users and a higher number of channel taps.  Nonlinear low-noise amplifiers give rise to distortion that partly combines coherently and limits the possible SINR.  It is concluded that spatial processing with a large number of antennas reduces the impact of hardware distortion in most cases.  As long as proper attention is paid to the few sources of coherent distortion, the hardware complexity can be reduced in massive MIMO base stations to overcome the hardware challenge and make massive MIMO commercial reality.
Massiv MIMO (eng: multiple-input–multiple-output) är en flerantennsteknologi för cellulär trådlös kommunikation, där basstationen använder ett stort antal individuellt styrbara antenner för att multiplexa användare i rummet.  Denna teknologi kan tillhandahålla en hög spektral effektivitet.  En av dess främsta utmaningar är den enorma hårdvarukomplexiteten och kostnaden hos basstationens alla radiokedjor.  För att massiv MIMO skall bli kommersiellt attraktivt, måste billiga, enkla hårdvarukomponenter med låg linjäritet användas, vilket oundvikligen leder till mer signaldistorsion.  Denna avhandling undersöker hur den försämrade linjäriteten hos några av huvudkomponenterna – effektförstärkare, analog-digital-omvandlare (AD-omvandlare) och lågbrusförstärkare – påverkar systemets prestanda, i termer av datatakt, effektförbrukning och utombandsstrålning.  Huvudresultaten är: Rumslig signalbehandling kan reducera sändsignalernas toppvärde i nerlänken ända ner till 0dB, vilket dock inte nödvändigtvis minskar effektförbrukningen.  I miljöer med isotrop fädning leder enbits-AD-omvandlare till 4dB lägre signal-till-interferens-och-brus-förhållande i upplänken, och fyrabits-AD-omvandlare ger en prestanda nära den ett system utan kvantisering kan uppnå.  Ett analytiskt uttryck för strålningsmönstret för distorsionen från icke-linjära effektförstärkare härleds.  Det visar hur distorsionen till viss del lobformas, att dess förstärkning aldrig är starkare än förstärkningen för den önskade signalen och att distorsionens förstärkning minskar med ett högre antal betjänade användare och ett högre antal kanaltappar.  Icke-linjära lågbrusförstärkare ger upphov distorsion som delvis kombinerar koherent och begränsar det möjliga signal-till-brus-och-interferens-förhållandet.  Slutsatsen är att rumslig signalbehandling med ett stort antal antenner reducerar hårdvarudistorsionens inverkan i de flesta fall.  Så länge som de få källorna till koherent distorsion ges tillbörlig uppmärksamhet, kan hårdvarukomplexiteten minskas i basstationer för massiv MIMO för att övervinna hårdvaruutmaningen och göra massiv MIMO kommersiell verklighet.
蜂窩無線通訊領域中的大規模多天線技術以多個單獨可控的天線通過空間複用的方式服務多個用戶。如是可以大幅提高頻譜效率。實現此技術的主要難題在於基站所用射頻單元的極大複雜度及成本。爲使大規模多天線技術適用在商業系統中,需使用導致失真的低複雜度低成本的非線性硬件。本文探討若將一些主要部件——功放、模數轉換器、低噪聲放大器——的線性程度降低,系統性能是如何受到影響的,即系統的速率、功耗、帶外泄露等指標。主要的結果爲:空間信號處理可以降低下行信號的峯均比,直至0分貝;然而低峯均比不一定能夠降低功耗。用一比特模數轉換器使上行的信干噪比減少4分貝;用四比特模數轉換器可在各向同性衰落的環境裏實現接近無量化系統的性能。本文推導出非線性功放失真輻射方向的解析公式。該公式展示失真在某種程度上會被波束成形的;具體而言,失真的波束成形增益不大於有效信號的增益,波束成形增益會根據服務用戶數量和信道階數的增長而降低。非線性低噪聲放大器引起的失真,一部分會相干地合併,因此會限制信干噪比的增長。結論爲多天線的空間信號處理可以減少硬件失真的影響。只要適當地處理少數相干失真的來源,大規模多天線基站可以降低硬件複雜度,解決硬件難題,使大規模多天線技術成功地應用在商業系統中成爲現實。
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Kamanzi, Janvier. "Development of a low energy cooling technology for a mobile satellite ground station". Thesis, Cape Peninsula University of Technology, 2013. http://hdl.handle.net/20.500.11838/1072.

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Thesis submitted in fulfillment of the requirements for the degree Master of Technology:Electrical Engineering in the Faculty ofEngineering at the Cape Peninsula University of Technology Supervisor:Prof MTE KAHN Bellville December 2013
The work presented in this thesis consists of the simulation of a cooling plant for a future mobile satellite ground station in order to minimize the effects of the thermal noise and to maintain comfort temperatures onboard the same station. Thermal problems encountered in mobile satellite ground stations are a source of poor quality signals and also of the premature destruction of the front end microwave amplifiers. In addition, they cause extreme discomfort to the mission operators aboard the mobile station especially in hot seasons. The main concerns of effective satellite system are the quality of the received signal and the lifespan of the front end low noise amplifier (LNA). Although the quality of the signal is affected by different sources of noise observed at various stages of a telecommunication system, thermal noise resulting from thermal agitation of electrons generated within the LNA is the predominant type. This thermal noise is the one that affects the sensitivity of the LNA and can lead to its destruction. Research indicated that this thermal noise can be minimized by using a suitable cooling system. A moveable truck was proposed as the equipment vehicle for a mobile ground station. In the process of the cooling system development, a detailed quantitative study on the effects of thermal noise on the LNA was conducted. To cool the LNA and the truck, a 2 kW solar electric vapor compression system was found the best for its compliance to the IEA standards: clean, human and environment friendly. The principal difficulty in the development of the cooling system was to design a photovoltaic topology that would ensure the solar panels were always exposed to the sun, regardless the situation of the truck. Simulation result suggested that a 3.3 kW three sided pyramid photovoltaic topology would be the most effective to supply the power to the cooling system. A battery system rated 48 V, 41.6 Ah was suggested to be charged by the PV system and then supply the power to the vapor compression system. The project was a success as the objective of this project has been met and the research questions were answered.
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Nwup, Emineimo Kennedy, e Adesola Idris Akande. "Evaluation of the pre IEEE 802.11s RFC : Aspects of the Design and Implementation of the Mesh Station with RA-OLSR in the C-Core". Thesis, Blekinge Tekniska Högskola, Avdelningen för telekommunikationssystem, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-3883.

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The demand for ubiquitous networks has pushed the designs of networks all the way. The requirement for access point to be integrated into IEEE 802.3 standard and other networks has always been a sore point in the limitation of wireless coverage of IEEE 802.11 standard networks. Wireless Mesh Network (WMN) is expected to be the future of the next generation wireless network. It is experiencing a fast growing development due to its attractive features which includes high reliable connectivity, easy deployment, self healing, self configuring, flexible network expansion etc. Hence the mobility of the WMN nodes has been of paramount importance, which would make it independent of wired infrastructure and flexible interoperability with various networks and devices. The requirements like mobility, transparency etc. have led to the amendment of the WMN standard by the Institute of Electronics and Electrical Engineering (IEEE) 802.11 Working Group (WG), Task Group (TG) “S. The IEEE 802.11s standard tackles these issues by its operation on layer 2 of Open Systems Interconnection (OSI) reference model and creates a transparent IEEE 802 broadcast domain that supports any higher layer protocol. In our work we give the evaluation of the upcoming IEEE 802.11s standard based on its features some of which include routing at layer 2 and medium access control to enable its design and implementation in the existing mesh frame work of Communication Research Labs (CRL) using the proposed IEEE 802.11s routing protocols with focus on RA-OLSR and HWMP. We concentrate on how to integrate these features into the existing CRL’s C-CORE which runs other layer 3 routing protocols and complex functions as Application Programming Interface (API) modules. The implementation of the IEEE 802.11s standard creates major challenges as we have to create a roadmap on integrating the new wireless kernel interfaces like the nl80211, cfg80211 and the Wireless Extension (Wext) into the CRL’s C-CORE framework for communication between user space and kernel space, especially taking into consideration of the existing HAL and madwifi wireless drivers of the CRL’s framework. To support the evaluation of the features like the layer 2 routing and the modified MAC performance, we compare results of the CRL’s real time mesh network test with our simulation result of the IEEE 802.11s standard using the Qualnet 4.5 simulator with focus on the basic network parameters like delay, jitter and throughput. The comparison shows that the CRL’s network has higher throughput running its existing layer 3 protocols. The analysis also proves that the 802.11s is flexible, scalable and efficient in delivering multi hop capabilities to clients that cannot afford the deployment time or the cost for wired networks that use access points. With the complete integration, of the 802.11s standard specifications the CRL’s C-CORE framework can be much more capable of supporting more diverse network scenario deployments.
+46-736318897
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Ali, Arslan [Verfasser], Georg [Akademischer Betreuer] Fischer, Georg [Gutachter] Fischer e Brink Stephan [Gutachter] ten. "Signal Integrity Analysis based on Higher Order Statistics for Inspection of Base Station and MIMO Array Imperfections and Compromitation / Arslan Ali ; Gutachter: Georg Fischer, Stephan ten Brink ; Betreuer: Georg Fischer". Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2021. http://d-nb.info/1238899013/34.

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Muñoz, Limay Katherine, e Rentería David Alonso Barrios. "Mejoramiento de calidad de servicio de señal abierta en una empresa televisiva de la Región de Ica". Bachelor's thesis, Universidad Ricardo Palma, 2015. http://cybertesis.urp.edu.pe/handle/urp/1289.

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La calidad de servicio de televisión de señal abierta en el Perú ha sido un inconveniente en las últimas décadas debido a la mala calidad que se brinda a los usuarios, la llegada de las implementaciones de estaciones terrestres digitales de la Televisión Digital Terrestre (TDT) podrá brindar a los ciudadanos de provincias y lugares lejanos una mejor calidad de imagen en sus televisores, en el cual están involucradas las emisoras televisivas. Una de las características de la señal de la televisión digital es la forma eficiente que tiene para transmitir en cualquier lugar, con alta calidad tanto en video como en audio, ofreciendo al usuario producto mucho mejor, con una de sus cualidades la interacción y acceso a información. En este trabajo se desea realizar una investigación adecuada para el mejoramiento de servicio de televisión de señal abierta de una empresa televisiva en la región de Ica, utilizando una estación terrena digital a través del estándar ISDB-Tb. Se utilizara el método de implementación de una estación terrena digital, con la finalidad de identificar los factores que influyen al ser implementadas con relación a las estaciones televisivas pequeñas. Se establecerá las diferencias que existen en la calidad de servicio para la transmisión análoga y digital en una señal abierta, ya sean sus ventajas o desventajas; y a la vez especificar el cambio que ocasionará al transmitir una señal abierta de estación televisiva pequeña a través de una señal digital. The quality of service television networks in Peru has been a drawback in recent decades due to the poor quality that users are provided, the arrival of the deployments of digital terrestrial stations of the Digital Terrestrial Television may giving citizens and far places better image quality on their TVs, which are involved in television stations. One feature of the digital tv signal is the efficient way it has to transmit anywhere, with high quality in both video and audio, providing users with better product, with one of his qualities interaction and access information. In this work we want to do adequate research to improve service broadcast television from a television company in the region of Ica, using a digital earth station through the ISDB-Tb standard. The method of implementing a digital earth station, in order to identify the factors that influence to be implemented in relation to small television stations were used. The differences in the quality of service for analog to digital signal transmission in an open, whether the advantages or disadvantages will be established; and simultaneously specify the change will cause a small open when transmitting television station signal through a digital signal.
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Ullrich, Robin. "Verfahren zur Punktidentifizierung bei der Qualitätskontrolle im Maschinenbau unter Verwendung von Polarmesssystemen". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-229911.

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In der heutigen Zeit wird die Qualitätssicherung von großen Produktionsgütern des Maschinen und Anlagenbaus vornehmlich durch flexibel einsetzbare Industrietachymeter oder Lasertracker vollzogen. Die vermessungstechnische Erfassung der qualitätsrelevanten Daten ist dabei in enge Prozessketten der Produktion eingebettet. Aufgrund dessen sind die Messabläufe meist softwareseitig gesteuert und gewährleisten eine vollständige und zeiteffiziente Erfassung aller Messpunkte. Damit die korrekte Überführung der Instrumentendaten in das Bezugssystem des Produkts sichergestellt werden kann, muss bei den Messungen ein besonderes Augenmerk auf die fehlerfreie Erfassung der Bezugs- und Verknüpfungspunkte gelegt werden. Im Rahmen der vorliegenden Arbeit wurden daher Identifizierungsverfahren erarbeitet, welche insbesondere für regelmäßige Bezugs- oder Verknüpfungspunktverteilungen zur sicheren Koordinatentransformation beitragen. Inhaltlich wird zwischen direkten und indirekten Identifizierungsstrategien unterschieden. Während die direkten Verfahren in erster Linie durch die Auswertung von Signalintensitäten eines Tachymeters gekennzeichnet sind, machen sich indirekte Verfahren zusätzliche Distanzdaten eines Funksystems zunutze. Speziell für die Anforderung der Verknüpfungspunktmessung vervollständigen punktidentifizierende Reflektorhalterungen das Anwendungsspektrum. Bei der direkten Identifizierungsvariante wurde das Konzept photogrammetrischer Zielzeichencodierungen aufgegriffen. Die Codierung der Zielmarke wird für tachymetrische Messungen durch verschieden stark reflektierende Zielmarkenbereiche erreicht, welche anhand der gemessenen Signalintensitäten voneinander trennbar sind. Mithilfe der empirisch ermittelten Instrumentenparameter zur Laserspotgröße und Intensitätsmessrate sowie Betrachtungen hinsichtlich minimaler Winkelgeschwindigkeiten wurde die Codeerfassung und -auswertung softwareseitig automatisiert. Die Validierung der Verfahren wurde mit einem Industrietachymeter Leica TDRA6000 für ring und sektorförmig codierte Zielmarken durchgeführt. Die Basis des indirekten Identifizierungsverfahrens ist die Kombination von Tachymeter- und Funkdaten. Der mobile Knoten eines Funksystems wurde dazu direkt am Tragegriff des Tachymeters angebracht und durch Bogenschnittverfahren im Bezugssystem positioniert. Angesichts der Vorinformation zur Mobilknotenposition wird die Identifizierung von tachymetrisch erfassten Bezugspunkten ermöglicht. Die Auswahl des Bezugspunkts wird aufgrund einer Kandidatenliste vollzogen, die in mehreren Filterstufen bis zum Verbleib eines einzigen Kandidaten reduziert wird. Neben definierten Distanzkriterien führen vor allem die Ergebnisse kandidatenbezogener Ausgleichungen mit Restriktionen zwischen den Unbekannten zur Identifizierung des Bezugspunkts. Das Konzept der funkgestützten Identifizierung wurde anhand einer Versuchsfeldanwendung verifiziert, wobei die Robustheit der Datenanalyse besonders durch die örtlichen Gegebenheiten des Maschinenbaus gefordert wird. Am Beispiel der Qualitätssicherung schienengebundener Fahrzeuge wurde zudem veranschaulicht, wie die Anwendung der direkten und indirekten Identifizierungsverfahren innerhalb eines strukturierten Messablaufes zur zeiteffizienten und sicheren Qualitätskontrolle beitragen kann.
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Nasri, Amin. "On the Dynamics and Statics of Power System Operation : Optimal Utilization of FACTS Devicesand Management of Wind Power Uncertainty". Doctoral thesis, KTH, Elektriska energisystem, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-154576.

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Nowadays, power systems are dealing with some new challenges raisedby the major changes that have been taken place since 80’s, e.g., deregu-lation in electricity markets, significant increase of electricity demands andmore recently large-scale integration of renewable energy resources such aswind power. Therefore, system operators must make some adjustments toaccommodate these changes into the future of power systems.One of the main challenges is maintaining the system stability since theextra stress caused by the above changes reduces the stability margin, andmay lead to rise of many undesirable phenomena. The other important chal-lenge is to cope with uncertainty and variability of renewable energy sourceswhich make power systems to become more stochastic in nature, and lesscontrollable.Flexible AC Transmission Systems (FACTS) have emerged as a solutionto help power systems with these new challenges. This thesis aims to ap-propriately utilize such devices in order to increase the transmission capacityand flexibility, improve the dynamic behavior of power systems and integratemore renewable energy into the system. To this end, the most appropriatelocations and settings of these controllable devices need to be determined.This thesis mainly looks at (i) rotor angle stability, i.e., small signal andtransient stability (ii) system operation under wind uncertainty. In the firstpart of this thesis, trajectory sensitivity analysis is used to determine themost suitable placement of FACTS devices for improving rotor angle sta-bility, while in the second part, optimal settings of such devices are foundto maximize the level of wind power integration. As a general conclusion,it was demonstrated that FACTS devices, installed in proper locations andtuned appropriately, are effective means to enhance the system stability andto handle wind uncertainty.The last objective of this thesis work is to propose an efficient solutionapproach based on Benders’ decomposition to solve a network-constrained acunit commitment problem in a wind-integrated power system. The numericalresults show validity, accuracy and efficiency of the proposed approach.

The Doctoral Degrees issued upon completion of the programme are issued by Comillas Pontifical University, Delft University of Technology and KTH Royal Institute of Technology. The invested degrees are official in Spain, the Netherlands and Sweden, respectively.QC 20141028

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37

Vieira, Pedro Rates. "Efeitos funcionais e filogenéticos nas relações entre forófitos e epífetos vasculares". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2012. http://hdl.handle.net/10183/144069.

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Os padrões de associação entre epífitos e forófitos não podem ser considerados espécie-específicos, mas as árvores que os epífitos colonizam também não são um conjunto aleatório das espécies forofíticas de um determinado local. Ao invés disso, parece haver uma preferência de certos epífitos por diferentes forófitos. No entanto, se conhece pouco sobre os fatores que determinam essa preferência. Nosso objetivo nesse trabalho é avaliar como os atributos funcionais e a filogenia dos epífitos vasculares influenciam na associação dos epífitos com os forófitos em uma Floresta Ombrófila Mista no sul do Brasil. Para isso nós (1) investigamos padrões de associação positiva e negativa entre grupos funcionais de epífitos e grupos de forófitos e como a diversidade e os atributos funcionais dos epífitos variavam em função do tamanho do forófito e (2) inferimos sobre a existência de sinal filogenético no uso de árvores hospedeiras pelos epífitos, procuramos por estrutura filogenética nas comunidades epifíticas e investigamos diferenças de composição filogenética de epífitos vasculares em diferentes clados de forófitos. Foram amostrados 70 forófitos compreendendo 15 espécies pertencentes a diversos clados e com arquiteturas e características variadas. A amostragem compreendeu 31 espécies epifíticas com os principais clados sendo Polypodiaceae, Bromeliaceae e Orchidaceae. A associação de grupos de epífitos vasculares com diferentes grupos de forófitos sugere que as características dos forófitos proporcionam ambientes contrastantes e que diferentes valores de atributos são necessários para colonizar esses ambientes. Mais especificamente espécies epifíticas com menor área específica foliar (SLA) parecem predominar em árvores maiores e maior SLA em árvores menores. Encontramos sinal filogenético na utilização dos forófitos, sugerindo que a conservação das interações com os forófitos deve ter sido importante ao longo da evolução dos epífitos. A tendência a agrupamento filogenético nas comunidades epifíticas sugere a influência de filtros ambientais representados pelas diferentes características dos forófitos estruturando as assembleias de epífitos. Clados mais basais de forófitos apresentaram composição filogenética distinta devido, sobretudo, a presença de diferentes clados de monilófitos epifíticos nessas árvores. Angiospermas epifíticas ocorreram principalmente em forófitos pertencente as eurosídeas. A preferência de epífitos por forófitos parece ser influenciada pelo surgimento de novidades morfológicas e ecofisiológicas em alguns clados, enquanto outros mantiveram o seu nicho ancestral. A composição florística das florestas quando da origem dos clados epifíticos também parece influenciar a associação entre epífitos e forófitos. Ao utilizar informações sobre os atributos e filogenia das espécies de epífitos vasculares nós podemos melhor compreender os mecanismos ecológicos e históricos que influenciam os padrões de associação entre epífitos e forófitos.
It has been shown that patterns of association between epiphytes and phorophytes can not be considered species-specific, although the trees that epiphytes colonize are not a random subset of phorophyte species in a particular location. Instead, there seems to be a preference of some epiphytes for different phorophytic species. However, little is known about the factors determining this choice. Our objective in this study is to assess how functional attributes and phylogeny of vascular epiphytes influence the association of epiphytes with the phorophytes in an Araucaria Forest in Southern Brazil. For that we (1) investigated the positive and negative association patterns between functional groups of epiphytes and groups of phorophytes and how functional diversity and functional traits of epiphytes varied with host tree size and (2) inferred about the existence of phylogenetic signal on the host trees use by epiphytes, looked for phylogenetic structure in the epiphytic communities and investigated differences in the phylogenetic composition of vascular epiphytes in different phorophyte clades. We used a sample of 70 phorophytes comprising 15 species and belonging to different clades and with different architectures and traits. The sample comprised 31 epiphytic species, the major clades being Polypodiaceae, Bromeliaceae and Orchidaceae. The combination of vascular epiphyte groups with different groups of 15 phorophytes suggests that phorophyte traits provide contrasting environments and that different trait values are needed to colonize these environments. More specifically, epiphytic species with lower specific leaf area (SLA) seem to predominate on larger trees and with higher SLA values on smaller trees. We found phylogenetic signal on the host tree use, suggesting that conservatism of the interactions with phorophytes must have been important throughout the evolution of epiphytes. The tendency to phylogenetic clustering in the epiphytic communities suggests the influence of environmental filters represented by phorophyte traits structuring epiphyte assemblages. More basal clades of phorophytes showed different phylogenetic composition mainly due to the presence of different epiphytic monilophyte clades on these trees. Epiphytic angiosperms occurred mainly on those trees belonging to eurosids. The preference of epiphytes for phorophytes seems to be influenced by morphological and ecophysiological novelties in some lineages, while other clades kept their ancestral niche. The floristic composition of forests at the origins of epiphytic lineages also appears to influence the association between epiphytes and phorophytes. By using information about the traits and phylogeny of species of vascular epiphytes we can better understand the ecological and historical mechanisms that influence the patterns of association between epiphytes and phorophytes.
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38

Hao, Yonggang. "Communications and radar signal processing for multiple base stations". 2007. https://scholarworks.umass.edu/dissertations/AAI3289260.

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This dissertation primarily focuses on design techniques for systems where multiple towers cover a given geographical area. In the first portion of this dissertation, these are communication towers and the goal is the reliable broadcast of information from these towers to mobile users. In the second portion of this dissertation, these towers are radars, and the goal is to recover the refractivity of the intervening atmosphere using phase measurements of the returned signal from various ground targets. Finally, in the third section, we depart from this general scenario and study transmission schemes on the wireless exchange channel. In macroscopic space-time coding, the codewords are spread across antennas at wide geographical separations instead of a single antenna array, as in standard space-time coding. Since the mobile users to whom the signals are transmitted can be spread across a wide geographical region, the times of arrival of the signal from different antennas are not identical across users. In contrast to standard space-time coding, codes under such a scenario must be robust to such relative differences. This demands more rigorous code designs. The performance criterion, the optimal receiver, and a family of code designs are discussed. In particular, a constructive code design for block codes and two trellis codes are presented. A matched filter bound analysis with associated numerical and simulation results demonstrates the robustness of the proposed code designs to the relative arrival times of the signals from different transmit antennas. Then, the matched filter bound analysis is extended to demonstrate significant improvements in coverage for such a system over currently employed systems and standard space-time coding approaches applied across the same set of transmit antennas. Retrieval of surface-layer refractivity via the method of Fabry is considered. A mathematical framework is constructed and signal processing algorithms derived that facilitate refractivity retrieval from the returns from multiple radars viewing a common geographical area. In particular, an approximate discrete model is derived to relate the measured phases to the surface layer refractivity fields, and a modified least-squares (LS) estimation algorithm is then proposed for the resulting, often ill-conditioned, inversion problem. Because the measurement technique is subject to modulo 2π uncertainties which impact retrievals, a novel algorithm, which jointly estimates the unwrapped phases and refractive index (RI) field, is also provided. Numerical results indicate the effectiveness of the derived algorithms in both the single and multiple radar case, as well as clearly establishing that having multiple views of the same geographical area from separate radars provides for significant improvement of the RI field estimates. Finally, the achievable rates of various transmission schemes for the exchange channel are studied. Network coding, where relay nodes combine the information received from multiple links rather than simply replicating and forwarding the received packets, has shown the promise of significantly improving system performance. In very recent works, multiple researchers have presented methods for increasing system throughput by employing network coding inspired methods to mix packets at the physical layer: physical-layer network coding (PNC). A common example used to validate much of this work is that of two sources exchanging information through a single intervening relay - a situation that we denote the "exchange channel''. In this dissertation, achievable rates of various schemes on the exchange channel are considered. Achievable rates for traditional multi-hop routing approaches, network coding approaches, and various PNC approaches are considered. A new method of PNC inspired by Tomlinson-Harashima precoding (THP), where a modulo peration is used to control the power at the relay, is introduced, and shown to have a slight advantage over analogous schemes at high SNRs.
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39

Leyonhjelm, Scott. "A digital signal processing solution for multichannel base stations". Thesis, 1995. https://vuir.vu.edu.au/15386/.

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Radio communication systems of the future will require a large increase in user capacity. To achieve this, cell sizes will reduce and the number of base stations will increase. Current base station architectures use analogue combining techniques which are expensive, voluminous and inflexible. This thesis investigates a Digital Signal Processing (DSP) solution which produces a cheaper, smaller and more flexible multichannel base station transmitter design. The main design challenges of the new DSP low power combining architecture are the multichannel combining algorithm, the frequency translation of the multichannel signal to radio frequency, the Digital to Analogue Conversion (DAC) interface and the wideband ultra-linear power amplifier. This thesis considers the pre-power amplifier stages.
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40

Shen, Sung-Chieh, e 沈嵩傑. "Analysis of Signal Quality and System Performance with Dynamic Traffic Load at Next Generation Femtocell Base Stations". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/57679647548538126349.

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碩士
國立中正大學
通訊工程研究所
99
International Mobile Telecommunication Advanced (IMT-Advanced) cellular system is defined by International Telecommunication Union (ITU). According to the ITU requirements, an IMT-Advanced cellular system must have target peak data rates up to 100 Mbit/s for high mobility such as mobile access and up to 1 Gbit/s for low mobility such as nomadic/local wireless access. IEEE 802.16m and 3GPP LTE-Advanced are two candidates of IMT-Advanced technology and both of them incorporate Femtocell Base Station into their next generation mobile network standards. Femtocell Base Station is a low power and low cost small base station in the customer premise. The aim of Femtocell is to improve indoor coverage, enhance system capacity and provide relief to Macrocell’s loading. How to make the most effective frequency sharing, interference management and radio resource allocation between macrocell base station and femtocell base station is a very important key technique. In the thesis, we consider a next-generation mobile communication network deploying both macrocell base stations and femtocell base stations. We compare the system performance when using different macro/femto spectrum resource allocation strategies. Furthermore, in contrast to previous studies that use independent placement of fixed number of users, we simulate users entering and leaving the system in a more realistic setting. This will allow us to do a more accurate evaluation of call blocking or outage probabilities.
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41

Bassoo, Vandana. "A digital up-conversion architecture for future high efficiency wireless base stations". Thesis, 2010. https://vuir.vu.edu.au/16051/.

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Over the past few years, there has been a growing need for wireless communications with higher data rates and ubiquitous coverage, and these must be achieved at reduced cost and with a lower carbon footprint. This evolution in wireless demand places a big burden on transmitter architectures. The need for higher efficiency has stimulated research into the potential replacement of current linear power amplifiers (PAs) by switch mode power amplifiers (SMPAs) at cellular frequencies. The radio frequency (RF) PA currently accounts for a significant part of the cost, and most of the power requirements of a typical wireless base station. This research is focused on the modulation and up-conversion circuits for generating the SMPA drive signals. The switched (‘on’/‘off’) nature of the amplifier drive signal creates an opportunity for an all-digital solution removing traditional analog components such as the digital to analog converters, reconstruction filters, quadrature modulator and local oscillators. Digital signal processing techniques used for signal modulation are extended to digital up-conversion to generate suitable drive signals for the SMPA. In this thesis, a sigma-delta (ΣΔ) based technique is used to embed a complex modulation scheme such as OFDM into a single ‘on’-‘off’ bit stream.
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42

Tsao, Kang-Ju, e 曹侃如. "Analysis of Signal Quality and System Performance with Different Power Setting Strategies at Next Generation Femtocell Base Stations". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/42274837424899641532.

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碩士
國立中正大學
通訊工程學系
98
International Mobile Telecommunication Advanced (IMT-Advanced) cellular system is defined by International Telecommunication Union (ITU). According to the ITU requirements, an IMT-Advanced cellular system must have target peak data rates up to 100 Mbit/s for high mobility such as mobile access and up to 1 Gbit/s for low mobility such as nomadic/local wireless access. IEEE 802.16m and 3GPP LTE-Advanced are two candidates of IMT-Advanced technology and both of them incorporate Femtocell Base Station into their next generation mobile network standards. Femtocell Base Station is a low power and low cost small base station in the customer premise. It connects to the core network via cable, DSL or similar backhaul technology. The aim of Femtocell is to improve indoor coverage, enhance system capacity and provide relief to Macrocell’s loading. In the thesis, we consider a WiMAX network deploying both Macrocells and Open Subscriber Group (OSG) Femtocells. Fisrt, the simulation results show that we can improve average SINR and average throughput by increasing the power level of OSG Femtocells within Macrocells. Second, we introduce a Femtocell Location-Dependent Power Setting (LDPS) scheme to improve indoor signal quality and reduced the power consumption of Femtocell Base Station. By adopting this power setting scheme, Femtocells away from the Macrocell Base Station only need low power setting to maintain indoor coverage, and the scheme also reduces the interference to surrounding users at the same time. Third, we fine-tune the power setting of LDPS scheme. The interference could be lowered by setting LDPS-Upper Bound at 23.2dBm for Femtocells near the cell center, and it won’t decrease the ratio of users connecting to Femtocells. And when we increase cell edge Femtocells’ LDPS-Lower Bound, cell edge users can get better signal quality from Femtocells.
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43

Pazahr, Shila. "Einfluss von Pravastatin auf die Kontraktion und auf die PI3K-Akt-Signal-Kaskade in isoliertem Kaninchen- und isoliertem insuffizienten Humanmyokard". Doctoral thesis, 2012. http://hdl.handle.net/11858/00-1735-0000-000D-F032-A.

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44

Bridges, Paul A. "Digital demodulation techniques for radio channels". Thesis, 1993. https://vuir.vu.edu.au/15572/.

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The basis of this research is directed towards the Private Mobile Radio (PMR) networks, which play significant roles in taxi, police, ambulance and other such services. With an ever increasing need for data transmission, the current PMR systems which were designed for voice are not adequate. This research will examine a digital modulation scheme which can co-exist with an analog system. The generation of the digital modulation will be examined in terms of Adjacent Channel Interference (ACI) requirements. Simulation techniques for the mobile radio channel are discussed, for evaluation of demodulator performance. Existing demodulation techniques were reviewed, with several of these simulated to find the most appropriate demodulation scheme for this application. This included the development of a new detection scheme. A test system using Digital Signal Processing (DSP) techniques was constructed.
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45

Zeng, Qingjie. "Performance Evaluation of Signage System in Subway Stations". Thesis, 2011. http://spectrum.library.concordia.ca/7259/1/Zeng_MASc_S2011.pdf.

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An information integrated, recognition accessible and format standardized signage system is not only a basic feature of a subway station, but also a factor that contributes to the smooth and well-organized operation of the subway service. To figure out the deficiency and limitation of existing signs in one subway station, and to further recover and improve the signage function, a comprehensive performance assessment of the signage system is necessary and compulsory, if not periodically, as least when major system modifications/enhancements are executed. In this study, a methodology is proposed to evaluate the signage performance from three aspects: information integration, visibility optimization and legibility standardization. Information integration requires a complete signage system in the station offering demanded and mandatory information to the public. It is examined via a comparison between the existing signs and a standardized signage system, which is defined in three stages: station element and passenger flow identification, signage definition and classification, and signage implementation. Visibility optimization means the signs should be set and installed in a proper way regarding to the color, panel size, lighting, orientation and height, to maximize their ability of drawing and facilitating passenger’s attention and recognition. The visibility of one sign is evaluated as one of the three levels: optimized visibility, limited visibility and impaired visibility. Legibility standardization introduces guidelines on format displaying of signs with respect to typeface, color application and information presentation, to achieve for passenger’s easy acceptance and understanding of signage information. Based on the methodology, an implementation flowchart is developed for generic signage evaluation in one subways station. A case study (Berri-UQAM Metro station) in Montreal city is tested as a step-by-step application of this methodology in a real-world system. The absent signs and signs that need improvement are identified in detail and the evaluation result is summarized, as basis for further ameliorative measures.
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46

WENG, CHI-CHENG, e 翁啟誠. "Research on FDD-LTE 2600MHz Wireless Base Station Signal Optimization Technology". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/8kbz85.

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碩士
國立勤益科技大學
電子工程系
107
With the fast development of electronic technology and the rapid development of wireless network technology, mobile Internet has become a necessity for many people, and users demand for high speed mobile network is increasing. Therefore, it is a very important issue to optimize the network coverage and the quality of mobile communication. The radiated RF signal will be limited by terrain, building, distance, frequency, platform height, antenna angle, transmit power, user device performance and other factors, furthermore will affect the actual transmission data rate performance. In order to maintain a relatively stable RF signal receiving during the operation of the mobile communication device, the mobile communication device relies on the valued wireless measurement device for signal testing and optimization. The main purpose of this thesis is to use the FDD-LTE 2600 frequency band as the testing band, by using sort mobile test software and devices to make some important telecommunication parameters measurement. The measurement results will be used for analysis and further improvement to improve the signal coverage and quality, and in addition to improve the benefits of mobile communication. Keyword : Nemo outdoor、Actix analyzer、Coverage optimization
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47

Li, Chunsheng. "MyD88, central relay station of interleukin 1 signaling pathway". Diss., 2005. http://etd.library.vanderbilt.edu/ETD-db/available/etd-12132005-122759/.

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48

Ming-JengHsu e 許鳴烝. "An Adaptive Signal Control Model for Inner Junction of the Taipei Bus Station". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/14615105145956185306.

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碩士
國立成功大學
交通管理學系碩博士班
100
Transit systems are solutions for the heavy travel demand problems of high-density areas, which play important roles in congestion mitigation, energy conservation and pollutant reduction. Improving bus arrival and departure on-time performance is a critical concern in reducing users’ wait and transfer time. Unlike a single-platform terminal, bus flow interruption in a multi-level-platform terminal could significantly reduce the service quality and deteriorate environmental condition. Significant congestion has been experienced during peak periods at a T-junction in the multi-platform bus terminal, Taipei Bus Station, recently launched in the heart of Taipei metropolitan area. Based on the findings for this issue of an analytical signal control model developed by Wei et al. (2011), a traffic demand forecasting model is needed to upgrade the existing pre-timed control strategy to dynamic control level. The artificial neural network approach is employed for constructing the demand forecasting model taking into account the relevant traffic flow information provided by the RFID readers embedded in the terminal monitoring systems in this research. Considering time-varying demand, this study developed an adaptive signal control model for managing bus traffic in Taipei Bus Station. An off-line operational performance is examined with historical data, followed by on-line preliminary testing by new data. In the case study, the proposed model has demonstrated itself very efficient in reducing congestion within the terminal.
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49

Liu, Chen-Yi, e 劉蓁宜. "Estimation Rainfall : Based on Received Signal StrengthIndicator of GSM in no Weather Station Environment". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/27198162322288218106.

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碩士
元智大學
電機工程學系
104
This study proposes a method, that people just hold mobile device which can received signal strength indicator (RSSI) of GSM, Then, based on RSSI reduction suffered by rain, the method can estimate rain rate in mobile device location, even the environment of location is no weather station. In the past research, some of them use rain rate to compensate rain attenuation of RSSI. The other research use rain attenuation of RSSI with the distance between base station and mobile device to estimate rain rate. In this study, we only use the RSSI measured by mobile device to estimate rain rate different from other research. This study is able to make up inadequate of density form weather stations. Reduce estimation error of rain rate in no weather stations environment. So people can know rain rate of their area and prevent disaster by rain rate. People can reduce the damage and protect their lives from the disaster of rain rate.
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50

HSIEH, CHI-TING, e 謝奇廷. "The Signal Decoding and Display Interface Designing of Coast Station Digital Selective Calling System". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/57372254326209133538.

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碩士
國立高雄海洋科技大學
電訊工程研究所
104
Taiwan is the main international maritime transport hub for Northeast Asia. Statistics from the Ministry of Transportation indicate that Taiwan’s import and export of goods by sea and the amount of growth year by year, in addition to daily foreign ships and fishing boats through waters surrounding Taiwan, are closely related to the ocean. In the frequent situation of maritime transport, Taiwan maritime traffic complexity and maritime risk environment have reached a certain degree of risk. Taiwan’s maritime traffic safety also discuss relevant international maritime laws and regulations in the White paper on Maritime Policy. The specification of navigation systems and equipment configuration in International Convention for the Safety of Life at Sea (SOLAS) shall be forced to carry Global Maritime Distress and Safety System (GMDSS). The aim of this thesis is mainly for Digital Selective Calling (DSC) under GMDSS to research and improve the situation which people need to stay different receiver of frequency bands. Because all equipment is from the foreign company that brings the problem of high cost and inconvenience in the future. We expect results of this thesis will display by the web page not only ships of the AIS signal through waters surrounding Taiwan but also ship’s accuracy location in distress situation.
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