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Ítem Sistemas MIMO como Alternativa para el Control del Efecto Multitrayectoria y de la Interferencia Co-Canal en Sistemas de Radio Móvil Satelital y Terrestre(Universidad Icesi, 2006-07-28) García Ariza, Alexis PaoloThe Multiple Inputs Multiple Outputs -MIMO- Systems are advanced technique both the radio signal fading control, problem associated to multipath effects, and co-channel interference mitigation in mobile systems, using array antennas and space- time processing.1 This technique lets improve the wireless systems performance and increase its data transmission capacity under dynamic environments. The paper presents both the basic concepts over multipath propagation in mobile satellite and terrestrial systems, and a research proposal in MIMO techniques for DS-CDMA systems. This research is presented to European Union for RadioGIS- UIS and MCG-UPV groups, supported by the Alban Program - High Level Scholarships for Latin America-. The research will be development at Communications Department of Polytechnic University of Valencia -UPV- like author’s Doctoral work.Ítem Carrier frequency effect on the MIMO eigenvalues in an indoor environment(Universidad Icesi, 2008-12-17) Reig, Juan; Llano Ramírez, Gonzalo; García Ariza, Alexis Paolo; Rubio, LorenzoThe effect of the carrier frequency on the multiple-input multiple-output (MIMO) system eigenvalues is investigated experimentally in an indoor environment considering lineof- sight (LOS) and non-line-of-sight (NLOS) conditions. The results show a reduction of the mean power gain in the MIMO system eigenvalues due to a correlation increment between the spatial subchannels when the carrier frequency increases. This effect causes a slightly reduction of the MIMO capacity.Ítem Análisis de irradiación electromagnética en las inmediaciones de una radio base sectorizada en condiciones andinas(Universidad Icesi, 2006-10-11) García Ariza, Alexis PaoloFor more than a year now, the Radio GIS Research Group, assisted by the Schools of Electrical, Electronic and Telecommunications Engineering (E3T) at UIS, together with other local research groups (i.e. ICESI´s I2T, UFPS’s GIDT, and UDI’s MAXWELL, and the Colombian Ministry of Communications have been conducting a number of studies on high-frequency electromagnetic radiation under outdoor conditions to determine acceptable human exposure levels to this kind of radiation. These studies are driven not only by academic interest in this subject, but also by concerns raised by communities in the city of Bucaramanga and other regions in Colombia with respect to the installation of a large number of radiocommunications stations. With this paper, the Radio GIS group makes some contributions, which will hopefully benefit both the population in general and the regulatory agencies, aiming at establishing control policies based on concrete theoretical and technical studies. The results of the studies discussed in this paper derive from previous research conducted in the field of electromagnetic propagationÍtem Medida, simulación y análisis de eficiencia espectral para canales MIMO en entornos indoor en la banda de 2GHz(Universidad Icesi, 2006-10-11) García Ariza, Alexis PaoloThe space-time wireless communication systems will use the advantages of the MIMO (Multiple Input Multiple Output) channels. Precedent studies have focused less attention on the capacity analysis considering correlated indoor channels under different frequency bands and polarizations. In practice, there is certain correlation degree between the different propagation sub-channels, which makes interesting to evaluate the impact that this correlation has on the system performance under different frequency bands and polarizations. The paper shows a detail study around of real MIMO channel and its spectral efficiency behavior when change both the number of antenna elements and SNR (Signal to Noise Ratio).Ítem Planificación de una red DVB-H en entorno urbano(Universidad Icesi, 2007-08-01) Gómez Barquero, David; García Ariza, Alexis Paolo; Cardona Marcet, Narcís; Monserra, José F.; Salieto, ArianaThis article analyzes the problem of DVB-H based mobile TV network planning, and specifically, the deployment cost minimization issue. The article presents the planning studies for a DVB-H network in the city of Valencia (Spain). A TV broadcasting tower and the base stations of a 3G cellular phone service provider were considered as the broadcasting sites. The network under studyinvolves synchronized transmitters at all the broadcast sites. In order to Þ nd network conÞ gurations yielding maximum coverage and minimum costs, a genetic multiobjective based algorithm was used. The obtained results show a high density of transmitters is needed in order to achieve satisfactory coverage levels in indoor environments, hence, the reusage of telecommunications infrastructure is a key factor in reducing the network deployment costs.