Made available in DSpace on 2014-06-12T17:39:43Z (GMT). No. of bitstreams: 2 arquivo6950_1.pdf: 2903411 bytes, checksum: 9ee987b0d8ab354e278b26df353e4fa3 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2006 / Desde seu surgimento, a telefonia sofreu constante evolução tecnológica. Na década de 70, surgiu uma nova necessidade: a mobilidade. Iniciou-se a era das comunicações móveis. A crescente integração dos sistemas celulares com a informática possibilitou o aparecimento de novas tecnologias e serviços às redes móveis. Atualmente, a telefonia celular digital tem como um dos principais representantes o GSM. Esse sistema especifica áreas de serviços bem definidas. Dentre essas áreas, uma que vem atraindo a atenção dos pesquisadores refere-se aos serviços de localização. Tais serviços utilizam o dispositivo móvel como ferramenta para a localização de seu portador. Para empregá-los nas redes móveis, é necessário o desenvolvimento de aplicações externas. A simulação surge como uma alternativa de apoio ao desenvolvimento dos aplicativos para os chamados serviços baseados em localização (LBS). Este trabalho descreve o desenvolvimento de um simulador para um dos componentes de um LBS. Trata-se de uma ferramenta que simula o serviço básico da plataforma de LBS da Siemens, informando a localização de dispositivos simulados. Essa ferramenta tem o objetivo de validar aplicações para LBS. O processo de desenvolvimento percorreu etapas bem definidas: especificação de funcionalidade; estudos de tecnologias e modelos que atendiam às necessidades; codificação em Java; documentação; e testes de validação. Atualmente, esse simulador encontra-se em uso por desenvolvedores

L’environnement électromagnétique ferroviaire se caractérise par la coexistence de signaux de formes d’ondes diverses adressant des problèmes de CEM de natures très différentes. Ces signaux dus à des sources qui occupent un spectre de fréquence étendu, sont parfois générés par des dispositifs de forte puissance. Les problèmes relèvent de domaines tels que l’énergie, la signalisation et la communication, et sont habituellement traités de façon disjointe. Leur résolution nécessite des méthodes d’analyse adaptées à chacune de ces problématiques. La mobilité et la présence d’interférences transitoires requièrent des méthodes d’analyse temps-fréquence. La majorité de ces méthodes utilisent la FFT pour ses temps de calcul performants. Cependant la FFT présente des limitations en termes d’adaptabilité aux systèmes très différents étudiés. Les bandes de fréquence ne sont pas ajustables, et les résolutions en temps et fréquence ne sont pas aisément adaptables à celles requises pour les systèmes considérés. Ce travail de thèse porte sur un outil global d’analyse en mesure de pallier certaines limitations. Les résolutions temporelle et fréquentielle peuvent être choisies en fonction du système étudié et des perturbations ciblées (transitoires ou permanentes), afin de relier les perturbations à l’impact qu’elles ont sur un système donné. Les bandes de fréquence analysées, les pas fréquentiel et temporel sont prédéfinis selon le système étudié, qu’il soit de basse ou de haute fréquence. Ces propriétés sont obtenues sans dégrader la rapidité de calcul, similaire à celle de la FFT et permettent l’implémentation de l’outil sur des équipements de mesure temps réel. / The railway electromagnetic environment is characterized by the coexistence of various signal waveforms which address very different EMC problems. These signals are produced by sources occupying a wide frequency spectrum, and can be generated by high-power devices. Associated EMC issues are in fields such as energy, signaling and communication, and are usually treated by different approaches. Their resolution requires analysis methods adapted to these different fields. The mobility and the presence of transient interferences can require time-frequency analysis methods. The majority of these methods uses the FFT due to its performing calculation time. However, the FFT is limited for adapting analysis resolution with the characteristics of different studied systems. The frequency bands are not adjustable, and the time and frequency steps are not readily adaptable to those required for the systems considered. This thesis work deals with a comprehensive analysis tool able to overcome some limitations. The time and frequency resolutions can be selected according to the studied system and the targeted disturbances (transient or permanent), in order to highlight the impact that the interferences have on a given system. The analyzed frequency bands, the frequency and time steps are predefined according to the studied system, whether low or high frequency devices. These properties are obtained without degrading the calculation time performances, which are similar to FFT and allow the implementation of this tool on real time measurement equipment.

<p>Mobile communications are a changing and really competitive market. Companies try to release new products and upgrade the old ones as soon as possible. And in this context it is where Ericsson Test Environment makes available to its customer one of the most comprehensive GSM test environments in the world.</p><p>The test site at customer disposal provides a good environment for testing purpose and it allows them to improve and develop their products in really interesting time terms.</p><p>To make this possible, a huge GSM network is enclosed inside its facilities and this entails some problem, mainly in the radio environment.</p><p>The main aim of this thesis work is to study the radio network from an EMC point of view, how all this equipment interacts to each other and to propose possible improvements in order to make a test environment more competitive. Moreover, it will be valued electric magnetic field in the plant with the intention to find out if is possible to warrantee an operation free of disruption in the equipment.</p>

<p>The purpose of this thesis is to build and then optimize a simulation environment for the GSM / EDGE / WCDMA receiver in the RF Asics.</p><p>The system generally consists of two blocks: an Agilent Advanced Design System (ADS) controlled system core and Simulation Environment System for Verification and Design (SEVED). The signal is generated by SEVED and directed into the system core, where the receiver under test is located. Signal output of the receiver is then directed back into SEVED for bit error rate calculations. Therefore the performance of the receiver can be evaluated.</p>

The purpose of this thesis is to build and then optimize a simulation environment for the GSM / EDGE / WCDMA receiver in the RF Asics. The system generally consists of two blocks: an Agilent Advanced Design System (ADS) controlled system core and Simulation Environment System for Verification and Design (SEVED). The signal is generated by SEVED and directed into the system core, where the receiver under test is located. Signal output of the receiver is then directed back into SEVED for bit error rate calculations. Therefore the performance of the receiver can be evaluated.

Ericsson in Linkoping houses one of the largest test laboratories within thewhole Ericsson Company. Mainly, the laboratories contain equipment forGSM, WCDMA and LTE. To test these systems, a quite large number ofRadio Base Stations are needed. The RBS's are housed in a proportionatelysmall area. Instead of sending signals through the air, cables are used totransfer the RF signals. In this way the equipment communicating witheach other are well speci ed. However this may not be the case if leakageoccur.This thesis work is about developing a system for monitoring the radioenvironment and detect leakages in the test site. There is a need to de newhat a leakage really is and measurements needs to be performed in order toaccomplish this. This report describes how the work has proceeded towardsthe nal implemented solution.

Mobile communications are a changing and really competitive market. Companies try to release new products and upgrade the old ones as soon as possible. And in this context it is where Ericsson Test Environment makes available to its customer one of the most comprehensive GSM test environments in the world. The test site at customer disposal provides a good environment for testing purpose and it allows them to improve and develop their products in really interesting time terms. To make this possible, a huge GSM network is enclosed inside its facilities and this entails some problem, mainly in the radio environment. The main aim of this thesis work is to study the radio network from an EMC point of view, how all this equipment interacts to each other and to propose possible improvements in order to make a test environment more competitive. Moreover, it will be valued electric magnetic field in the plant with the intention to find out if is possible to warrantee an operation free of disruption in the equipment.

The primary objective of this thesis is to design advanced interference resilient schemes for asynchronous slow frequency hopping wireless personal area networks (FH-WPAN) and time division multiple access (TDMA) cellular systems in interference dominant environments. We also propose an interference-resilient power allocation method for multiple-input-multiple-output (MIMO) systems. For asynchronous FH-WPANs in the presence of frequent packet collisions, we propose a single antenna interference canceling dual decision feedback (IC-DDF) receiver based on joint maximum likelihood (ML) detection and recursive least squares (RLS) channel estimation. For the system level performance evaluation, we propose a novel geometric method that combines bit error rate (BER) and the spatial distribution of the traffic load of CCI for the computation of packet error rate (PER). We also derived the probabilities of packet collision in multiple asynchronous FH-WPANs with uniform and nonuniform traffic patterns. For the design of TDMA receivers resilient to CCI in frequency selective channels, we propose a soft output joint detection interference rejection combining delayed decision feedback sequence estimation (JD IRC-DDFSE) scheme. In the proposed scheme, IRC suppresses the CCI, while DDFSE equalizes ISI with reduced complexity. Also, the soft outputs are generated from IRC-DDFSE decision metric to improve the performance of iterative or non-iterative type soft-input outer code decoders. For the design of interference resilient power allocation scheme in MIMO systems, we investigate an adaptive power allocation method using subset antenna transmission (SAT) techniques. Motivated by the observation of capacity imbalance among the multiple parallel sub-channels, the SAT method achieves high spectral efficiency by allocating power on a selected transmit antenna subset. For 4 x 4 V-BLAST MIMO systems, the proposed scheme with SAT showed analogous results. Adaptive modulation schemes combined with the proposed method increase the capacity gains. From a feasibility viewpoint, the proposed method is a practical solution to CCI-limited MIMO systems since it does not require the channel state information (CSI) of CCI.

Increases in bandwidth and computational speed lead to growing interests in real-time audio and video communication over the Internet. With dramatic increase in wireless access recently, a challenging problem associated with audio and video communication lies in how to cope with packet loss and achieve acceptable video quality at the receiver and utilizing the limited wireless bandwidth efficiently. In this paper, we implement a system, Personal Mobile Communicator, to offer video and audio streaming communication. We employ MPEG-4 and GSM to compress video and audio data. MPEG-4 and GSM provide the standardized technological elements to compress video and audio data. MPEG-4 also takes a number of steps to enable robust transmission of compressed video data over noisy communication channels. We implement error resilience tools for reliable transmission and error concealment technologies to provide better video quality when error occurred. The goal of this paper, we design a communication system that is suitable for communication over wireless channel and offer a verification platform for further research.

The analysis of the possibilities of the determination of moving objects by the means of GSM nets.