Search results for "comunicació"
showing 10 items of 976 documents
Resource allocation for clustered network MIMO OFDMA systems
2012
In this article, we address the resource allocation problem for the downlink of a large network multiple input multiple output orthogonal frequency division multiplexing system with 3-sector base stations. The system is statically divided into a number of disjoint clusters of sectors. A two-step resource allocation scheme is proposed involving the inter-cluster and the intra-cluster levels. As a first step or inter-cluster level, two cooperative frequency reuse approaches are designed to mitigate the inter-cluster interference. A user partition method is proposed to divide the users of each cluster into cluster-edge and cluster-center users. To balance the cell-edge and the cell-average per…
Performance of power control in inter-cell interference coordination for frequency reuse
2010
To mitigate inter-cell interference in 3G evolution systems, a novel inter-cell interference coordination scheme called soft fractional frequency reuse is proposed in this article, which enables to improve the data rate in cell-edge. On this basis, an inter-cell power control is presented for the inter-cell interference coordination, and the inter-cell balanced signal to interference plus noise ratio (SINR) among users is established for power allocation, which enables mitigation of inter-cell interference. Especially, the power control is based on a novel exponential kernel equation at higher convergence speed than the traditional arithmetic kernel equations. Numerical results show that th…
Downlink radio resource allocation for coordinated cellular OFDMA networks
2010
Base station coordination is considered as a promising technique to mitigate inter-cell interference and improve the cell-edge performance in cellular orthogonal frequency division multiple-access (OFDMA) networks. The problem to design an efficient radio resource allocation scheme for coordinated cellular OFDMA networks incorporating base station coordination has been only partially investigated. In this contribution, a novel radio resource allocation algorithm with universal frequency reuse is proposed to support base station coordinated transmission. Firstly, with the assumption of global coordination between all base station sectors in the network, a coordinated subchannel assignment al…
Error mitigation using RaptorQ codes in an experimental indoor free space optical link under the influence of turbulence
2015
In free space optical (FSO) communications, several factors can strongly affect the link quality. Among them, one of the most important impairments that can degrade the FSO link quality and its reliability even under the clear sky conditions consists of optical turbulence. In this work, the authors investigate the generation of both weak and moderate turbulence regimes in an indoor environment to assess the FSO link quality. In particular, they show that, due to the presence of the turbulence, the link experiences both erasure errors and packet losses during transmission, and also compare the experimental statistical distribution of samples with the predicted Gamma Gamma model. Furthermore,…
Power allocation for two-cell two-user joint transmission
2012
In this paper, we develop a power allocation scheme for the downlink of a two-cell two-user joint transmission system. The objective is to maximize the sum rate under per-cell power constraints. We study a worst case scenario where the carrier phases between the two base stations are un-synchronized, so that joint transmission must be performed without precoding. The derived power allocation scheme is remarkably simple, i.e., each cell transmits with full power to only one user. Note that joint transmission is still possible, when two cells select the same user for data transmission. Moreover, we prove that, in this scenario, the joint transmission case happens with higher probability when …
The Information and Communication Technologies in the school sys-tem. A review of the research lines
2005
This paper offers a classification of research trends and perspectives about processes oriented to incorporate information and communication technologies (ICT) in schools. Identified are four research trends: a) studies about indicators of computers quantity in school systems; b) studies about computer effects in learning; c) studies about opinion, perspectives and attitudes of educational agents to ICT; and d) studies about computers' educational use in classroom and colleges. This paper finishes with a synthesis of current knowledge about projects and programs intended for the embodiment of ICT in school systems.
Comunicación y decrecimiento.
2013
El concepto de saturación comunicativa no es nuevo en el campo de la investigación en comunicación. Desde diferentes enfoques (lingüístico, psicológico, económico...) ha sido un tema de preocupación en relación con la comprensión de los fenómenos comunicativos modernos. En el presente trabajo tratamos de articular una relación novedosa del concepto comunicativo con una idea próxima al ámbito de la ecología: el decrecimiento. Se trata, en este sentido, de una propuesta encaminada a hacer visible una acuciante necesidad; a saber la de limitar, filtrar y seleccionar el imponente volumen de información con el que manejarse en la cotidianeidad. Se trata, asimismo, de una aproximación teórica en …
Breve estudio de los orígenes de la sinología alemana y de la expansión del daoísmo
2017
The dissemination of Daoism in the West is a process that, although it begins late and slow, will lead to the great interest that this way of thinking has finally awakened, not only in the academic field, but also in some popular media.
La participación de la prensa de Cataluña en la construcción de la homofobia como problema social (2012-2014)
2017
El Parlament de Cataluña aprobó el 04/10/2014 una ley pionera en España para erradicar la homofobia. Esta investigación analiza cuantitativamente qué cobertura sobre la violencia contra gays y lesbianas ofrecieron los dos diarios más vendidos en Cataluña (La Vanguardia y El Periódico) desde el arranque de la X legislatura (17/12/2012) con el objetivo de determinar si estos diarios favorecieron una representación de la homofobia como problema social, tanto en su discurso informativo como en sus artículos de opinión, y establecer comparaciones entre ambas cabeceras. La hipótesis de partida señala que la cobertura de casos de violencia homófoba será elevada, pese a que se espera una mayor pres…
El teléfono móvil desde la dimensión social y educativa en la didáctica de las artes visuales
2019
El presente artículo forma parte de una amplia investigación relativa al uso del teléfono móvil en la formación universitaria de futuros maestros, en la didáctica de la Expresión Plástica de la Facultad de Magisterio de la Universitat de València. En adelante exponemos la dimensión del teléfono móvil como una herramienta social y educativa en la didáctica de las artes visuales. La evolución de este dispositivo en su breve pero intensa trayectoria puede facilitar en nuestra área de conocimiento el trabajo mediante imágenes. Las redes sociales son otro de los agentes que se presentan como espacio virtual que posibilita a los estudiantes interactuar entre los lindes de la educación formal y la…