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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Simulation and Performance evaluation of co-existing GSM and UMTS systems

Cutillas Sanchez, Laura January 2010 (has links)
<p> </p><p>Mobile users need more capacity and higher velocity to work with new data applications. In </p><p>order to satisfy these requirements, mobile systems of third generation were created and they </p><p>are established every day in more places. Consequently second and third generation of system </p><p>have to coexist. </p><p>In this paper is presented a study about the co-existence between GSM and UMTS, the most </p><p>popular systems in Europe. 900MHz is the frequency chosen to work with both systems, due to </p><p>this low frequency allows: less path loss and more coverage, than 2100MHz the usual </p><p>frequency for UMTS system.  </p><p>The situation evaluated is focused on introducing a UMTS carrier in a GSM operator, with the </p><p>aim to determine the advantages and cons produced in the mobiles with this change. Two </p><p>cases are distinguished: coordinated operation, GSM and UMTS900 in the same operator and </p><p>un-coordinated operation, UMTS900 respect to other GSM operator. Users under study belong </p><p>to both modified operator and a next GSM operator. Power control was programmed in both </p><p>systems. </p><p>It was determined how affect the interferences in system capacity of the operators and which </p><p>is the guard band necessary to protect the system. Spectral efficiency (user/cluster/MHz) in </p><p>the case GSM and UMTS900 in same band is twice as much as in a GSM operator. The </p><p>separation between operators is set in 300KHz.But is important to know that UMTS carriers do </p><p>not cause damage in others operators because is located in the middle of GSM carriers. The </p><p>guard band fixed to protect each mobile in operator with shared spectrum is not necessary. </p><p>The distance between carriers GSM and UMTS necessary is 2.4MHz while the width of one </p><p>UMTS carrier is 2.5MHz. </p>
2

Simulation and Performance evaluation of co-existing GSM and UMTS systems

Cutillas Sanchez, Laura January 2010 (has links)
Mobile users need more capacity and higher velocity to work with new data applications. In  order to satisfy these requirements, mobile systems of third generation were created and they  are established every day in more places. Consequently second and third generation of system  have to coexist.  In this paper is presented a study about the co-existence between GSM and UMTS, the most  popular systems in Europe. 900MHz is the frequency chosen to work with both systems, due to  this low frequency allows: less path loss and more coverage, than 2100MHz the usual  frequency for UMTS system.   The situation evaluated is focused on introducing a UMTS carrier in a GSM operator, with the  aim to determine the advantages and cons produced in the mobiles with this change. Two  cases are distinguished: coordinated operation, GSM and UMTS900 in the same operator and  un-coordinated operation, UMTS900 respect to other GSM operator. Users under study belong  to both modified operator and a next GSM operator. Power control was programmed in both  systems.  It was determined how affect the interferences in system capacity of the operators and which  is the guard band necessary to protect the system. Spectral efficiency (user/cluster/MHz) in  the case GSM and UMTS900 in same band is twice as much as in a GSM operator. The  separation between operators is set in 300KHz.But is important to know that UMTS carriers do  not cause damage in others operators because is located in the middle of GSM carriers. The  guard band fixed to protect each mobile in operator with shared spectrum is not necessary.  The distance between carriers GSM and UMTS necessary is 2.4MHz while the width of one  UMTS carrier is 2.5MHz.
3

Reduced-complexity equalization for EDGE

Chow, N. H. January 2003 (has links)
Enhanced Data Rates for GSM Evolution (EDGE) is currently being standardized as the evolution path for GSM. EDGE improves the spectral efficiency by employing an 8PSK modulation scheme with 3pi/8 rotation between symbols, which triples the GSM data rate. A Linearized-GMSK pulse shaping filter is employed to remain within the 200kHz bandwidth of GSM. In order to facilitate the ease of transition from GSM to EDGE, system parameters such as symbol rate and time slot structure remain unchanged. As a result, a network capable of EDGE can be deployed with limited investment and within a short time frame, with just an upgrade in the transceiver and the system software. The introduction of EDGE modulation has a significant effect in the receiver. The LGMSK filter introduces Inter-symbol interference whose effect becomes severe due to multi-path fading and Doppler Spreading. In addition, 8-PSK has a smaller Euclidean distance between symbols than GMSK, which makes EDGE more prone to errors. Therefore a robust equalizer is required. The research objective is to mitigate the effects of fast time-varying frequency selective fading channels in the presence of noise and interference, by optimizing the trade-off between complexity and performance. This leads to four main areas of study: Reduced-state Equalization, Pre-filtering, Reduced-state Soft Output Equalization and Joint Pre-filter, Channel and Reduced State Soft Output Data Estimation. The optimum scheme. Maximum Likelihood Sequence Estimation, based on the Viterbi Algorithm, for a 6-tap channel requires 32768 (85) trellis states. Using the techniques developed in this thesis, an implementation margin of 5.9 dB over the EDGE standard requirement is achieved with only a 2 trellis state equalizer. Subsequently, based on this low complexity structure, a new method is developed involving two stages of equalizers in cascade. With reduced decision errors and improved noise variance estimation, the two stage scheme leads to a performance surpassing the single stage, with good resistance to interference. Finally, a joint scheme of moderate complexity is developed to support the scenario of a high speed train.
4

Návrh rádiové sítě GSM-R na železniční trati včetně návrhu konektivity k základnovým stanicím BTS / GSM-R radio network design at the railroad including base station connectivity

Řehák, Martin January 2017 (has links)
This diploma thesis deals with the design of the radio network for the track section Břeclav-Znojmo. Firstly, the theoretical knowledge about GSM-R, Radiolab and radio relay is described. The next part deals with the measurement of the already covered section of the track and the selection of a suitable propagation model. Radiolab is designed to cover several diffusion models. The model used for the final design of the network is chosen based on the comparison of the measurement results with the proposed coverage in Radiolab. The last part describes the provision of connectivity to individual base stations. Several connectivity options are compared.
5

Predictive Mobility Management for future mobile telecommunication networks

Kiss, Zoltan January 2000 (has links)
No description available.
6

Diseño de un sistema de monitoreo de parámetros eléctricos basados en tecnología GSM para un riogenerador PUCP

Romero Rodríguez, Diego Ely 17 August 2015 (has links)
En la actualidad, los sistemas de monitoreo a distancia son usados por empresas que necesitan conocer el estado y funcionamiento de sus equipos o de un sistema en particular. El monitoreo es realizado de forma remota porque los equipos se encuentran ubicados en lugares alejados de las oficinas de las empresas o en lugares donde el acceso es restringido. En particular, un regulador de carga de un riogenerador, es un dispositivo que tiene por finalidad producir el acople correcto entre una fuente de energía eléctrica, las baterías y los elementos de consumo. Con la finalidad de conocer el funcionamiento adecuado de este dispositivo, es necesario el monitoreo constante de dos parámetros: voltaje y corriente. Sin embargo, al estar ubicado en un lugar distante, requiere un enlace vía una red de telecomunicaciones, tal como GSM. El objetivo de esta tesis es el diseño de un sistema de monitoreo de parámetros eléctricos de un riogenerador PUCP, empleando tecnología GSM. Para determinar la operatividad del riogenerador, se eligió monitorear constantemente el voltaje y la corriente entre el regulador de carga y sus baterías. Este riogenerador, construido por el Grupo PUCP, tiene como finalidad generar energía eléctrica para zonas rurales aprovechando el caudal de un río. Para alcanzar este objetivo, se analizará el estado del arte de la tecnología existente, que se emplea en un sistema de monitoreo a distancia a fin de realizar la elección óptima de sus elementos. Estas decisiones incluyen la selección de los sensores, el diseño de las etapas de acondicionamiento, la programación de un microcontrolador, el desarrollo de una interfaz web y el suministro de energía solar del sistema de monitoreo. Al final, se realizan pruebas para comprobar y validar su funcionamiento. / Tesis
7

GSM-baserat larm

Cartemo, Henrik, Ivehag, Tobias January 2004 (has links)
No description available.
8

Statistics based automatic triggering of a mobile radio frequency optimization tool

Brandtson, Kristian January 2004 (has links)
No description available.
9

GSM-baserat larm

Cartemo, Henrik, Ivehag, Tobias January 2004 (has links)
No description available.
10

Statistics based automatic triggering of a mobile radio frequency optimization tool

Brandtson, Kristian January 2004 (has links)
No description available.

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