Ara es mostren els items 70-89 de 252

    • Design of an hybrid ground-space architecture based on individual on-board antenna power optimization for the forward link of a multi-beam broadband satellite system 

      Joroughi, Vahid; Vazquez, Miguel Angel; Devillers, Bertrand; Pérez Neira, Ana Isabel (2013)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      The multi-beam broadband satellite systems have been deployed to provide broadband services to their under-served geo-graphical area. In one hand, with assuming full frequency reuse among beams the resulting interference ...
    • Design of an on-board beam generation process for the forward link of a multibeam broadband satellite system 

      Joroughi, Vahid; Devillers, Bertrand; Vazquez, Miguel Angel; Pérez Neira, Ana Isabel (Institute of Electrical and Electronics Engineers (IEEE), 2013)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      The multi-beam broadband satellite systems have been deployed to provide broadband services to their under-served geo-graphical area. In one hand, with assuming full frequency reuse among beams the resulting interference ...
    • Design of pre-coding and combining in hybrid analog-digital massive MIMO with phase noise 

      Corvaja, Roberto; García Armada, Ana; Vazquez, Miguel Angel; Pérez Neira, Ana Isabel (Institute of Electrical and Electronics Engineers (IEEE), 2017)
      Text en actes de congrés
      Accés restringit per acord de confidencialitat
      The design of massive MIMO, especially at millimeter waves, requires a trade-off between cost and power consumption, balancing the complexity and the performance in terms of achievable rate. A recent trend in the design ...
    • Differential feedback in MIMO communications: performance with delay and real channel measurements 

      Sacristán Murga, Daniel; Kaltenberger, Florian; Pascual Iserte, Antonio; Pérez Neira, Ana Isabel (2009-02)
      Text en actes de congrés
      Accés obert
    • Dimensionality constraints imposed by highly frequency selective channels on MIMO-FBMC / OQAM systems 

      Pérez Neira, Ana Isabel; Caus, Marius (VDE Conference Publications, 2015)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      This paper investigates the application of MIMO to the FBMC/OQAM scheme in highly frequency selective channels. The system model that is considered in this work does not make any assumption about the flatness of the channel. ...
    • Distance-aware coordinated multi-point transmission for terahertz band communication 

      Dowhuszko, Alexis; Gil Jiménez, Víctor P.; Genovés Guzmán, Borja; Pérez Neira, Ana Isabel (Institute of Electrical and Electronics Engineers (IEEE), 2017)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      Terahertz (THz) band communication has abundant spectral resources to accommodate multiple broadband carriers. However, the strong path loss attenuation and the limited transmission power affect the maximum number of ...
    • Distributed power control with received power constraints for time-area-spectrum licenses 

      Pérez Neira, Ana Isabel; Veciana Fontanet, Joaquim Maria; Vázquez, Miguel Ángel; Lagunas, Eva (2016-03)
      Article
      Accés obert
      This paper deals with the problem of optimal decentralized power control in systems whose spectrum is regulated in time and space, the so-called time-area-spectrum (TAS) licensed. This license system gives to the owner the ...
    • Dual polarized modulation and reception for next generation mobile satellite communications 

      Henarejos Hernández, Pol; Pérez Neira, Ana Isabel (2015-10-01)
      Article
      Accés obert
      This paper presents the novel application of polarized modulation (PMod) for increasing the throughput in mobile satellite transmissions. One of the major drawbacks in mobile satellite communications is the fact that the ...
    • DVB-T candidate power detector for cognitive radio 

      Rojas, Miguel A.; Pérez Neira, Ana Isabel; Lagunas Hernandez, Miguel A. (2009)
      Text en actes de congrés
      Accés obert
      Dynamic detection of primary users is one of the main functions of spectrum sensing for Cognitive Radio (CR) communications aiming to increase the use of radio spectrum. In this work the performance of the so-called ...
    • Dynamic bit allocation and differential quantization in feedback link for robust power allocation in multiuser opportunistic beamforming 

      Zorba, Nizar; Pascual Iserte, Antonio; Pérez Neira, Ana Isabel (2008)
      Text en actes de congrés
      Accés obert
      Multi-antenna systems provide advantages in terms of link quality and multiuser access capabilities, which can be achieved by using schemes as multibeam opportunistic beamforming. This scheme only requires partial channel ...
    • Edge computing and communication for energy-efficient earth surveillance with LEO satellites 

      Martínez Gost, Marc; Leyva-Mayorga, Israel; Pérez Neira, Ana Isabel; Vázquez Oliver, Miguel Ángel; Soret, Beatriz; Moretti, Marco (Institute of Electrical and Electronics Engineers (IEEE), 2022)
      Comunicació de congrés
      Accés obert
      Modern satellites deployed in low Earth orbit (LEO) accommodate processing payloads that can be exploited for edge computing. Furthermore, by implementing inter-satellite links, the LEO satellites in a constellation can ...
    • Efficient margin adaptive scheduling for MIMO-OFDMA systems 

      Moretti, Marco; Pérez Neira, Ana Isabel (2013-01)
      Article
      Accés restringit per política de l'editorial
      In this paper we address the problem of margin adaptive scheduling in the downlink of an orthogonal frequency division multiple access (OFDMA) multiple-input multiple-output (MIMO) system. Optimal resource allocation in ...
    • Energy efficiency communications over the AWGN relay channel 

      Gómez Vilardebó, Jesús; Pérez Neira, Ana Isabel; Nájar Martón, Montserrat (2010)
      Article
      Accés restringit per política de l'editorial
      This paper addresses the energy efficiency analysis of the relay channel under additive white Gaussian noise. We consider the rate bounds given by decode and forward and the cut set bound and assume that resources are ...
    • Energy efficient communications over the AWGN relay channel 

      Gómez Vilardebó, Jesús; Pérez Neira, Ana Isabel; Nájar Martón, Montserrat (2010-01-08)
      Article
      Accés obert
      This paper addresses the energy efficiency analysis of the relay channel under additive white Gaussian noise. We consider the rate bounds given by decode and forward and the cut set bound and assume that resources are ...
    • Enhancing cell-free massive MIMO networks through LEO satellite integration 

      Riera Palou, Felip; Femenias Nadal, Guillem; Caus López, Màrius; Shaat, Musbah; García Morales, Jan; Pérez Neira, Ana Isabel (Institute of Electrical and Electronics Engineers (IEEE), 2021)
      Text en actes de congrés
      Accés obert
      This paper proposes a hybrid network architecture combining a cell-free Massive MIMO terrestrial layout with a low Earth orbit satellite segment jointly targeting the maximization of the minimum per-user rate in the coverage ...
    • ENN: a neural network with DCT adaptive activation functions 

      Martínez Gost, Marc; Pérez Neira, Ana Isabel; Lagunas Hernandez, Miguel A. (Institute of Electrical and Electronics Engineers (IEEE), 2024-02-01)
      Article
      Accés obert
      The expressiveness of neural networks highly depends on the nature of the activation function, although these are usually assumed predefined and fixed during the training stage. Under a signal processing perspective, in ...
    • Error rate analysis and optimal power allocation in multiple access relay channels with analog network coding 

      Ntontin, Konstantinos; Di Renzo, Marco; Pérez Neira, Ana Isabel; Verikoukis, Christos (Institute of Electrical and Electronics Engineers (IEEE), 2014)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      In this paper, we examine multi-source multi-relay systems that employ Analog Network Coding for which we provide a two-fold contribution: i) We derive a closed-form upper bound of the average symbol error rate (SER) ...
    • Estimación recursiva simultánea de potencia y DOA por ajuste de la matriz de covarianza asociada a la apertura 

      Pérez Neira, Ana Isabel; Lagunas Hernandez, Miguel A. (1992)
      Text en actes de congrés
      Accés obert
      The small error approximation is used to derive a linear relationship between the source parameters (i.e. power levels and directions of arrival or DOA's) and a measurement of the covariance error matrix, defined as the ...
    • Evaluation of spectrum opportunities in the GSM band 

      Carniani, Andrea; Giupponi, Lorenza; Verdone, Roberto; Pérez Neira, Ana Isabel (2009)
      Text en actes de congrés
      Accés obert
      In this paper we explore the possibility of exploiting underutilized channels in the GSM bands. The secondary (unlicensed) users of the spectrum are the nodes of an overlay cognitive ad-hoc network, which opportunistically ...
    • Evolution of spatial and multicarrier scheduling: towards multi-cell scenario 

      Henarejos Hernández, Pol; Pérez Neira, Ana Isabel; Tralli, Velio; Moretti, Marco; Dimitriou, Nikos; Dainelli, Giulio (2010)
      Text en actes de congrés
      Accés obert
      OFDMA systems are considered as the promising multiple access scheme of next generation multi-cellular wireless systems. In order to ensure the optimum usage of radio resources, OFDMA radio resource management algorithms ...