Ara es mostren els items 109-128 de 134

    • REAVALUACIÓ 

      Nájar Martón, Montserrat; Pagès Zamora, Alba Maria; Riba Sagarra, Jaume; Vázquez Grau, Gregorio (Universitat Politècnica de Catalunya, 2022-07-05)
      Examen
      Accés restringit a la comunitat UPC
    • Redundancy in block coded modulations for channel equalization based on spatial and temporal diversity 

      Vázquez Grau, Gregorio; Rey Micolau, Francesc; Lamarca Orozco, M. Meritxell (Institute of Electrical and Electronics Engineers (IEEE), 1999)
      Text en actes de congrés
      Accés obert
      Linear block codes in the complex field can be applied in spatial and/or temporal diversity receivers in order to develop high performance schemes for (almost-) blind equalization in mobile communications. The proposed ...
    • Robust beamforming for interference rejection in mobile communications 

      Riba Sagarra, Jaume; Goldberg, Jason; Vázquez Grau, Gregorio (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 1997-01-01)
      Article
      Accés obert
      The problem of robust beamformer design for mobile communications applications in the presence of moving co-channel sources is addressed. A generalization of the optimum beamformer based on a statistical model accounting ...
    • Robust beamforming for interference rejection in mobile communications 

      Riba Sagarra, Jaume; Goldberg, J; Vázquez Grau, Gregorio (1996)
      Text en actes de congrés
      Accés obert
      The problem of robust beamformer design in the presence of moving sources is considered. A new technique based on a generalization of the constrained minimum variance beamformer is proposed. The method explicitly takes ...
    • Robust data detection in asynchronous DS-CDMA in the presence of timing uncertainty 

      Riba Sagarra, Jaume; Goldberg, J; Vázquez Grau, Gregorio (IEEE, 1996)
      Text en actes de congrés
      Accés obert
      The decorrelating and minimum mean squared error data detectors for direct sequence code division multiple access (DS-CDMA) communications systems are known to exhibit low vulnerability to the near-far problem. Nevertheless, ...
    • Robust estimation of the magnitude squared coherence based on Kernel signal processing 

      Cabrera Estanyol, Ferran de; Riba Sagarra, Jaume; Vázquez Grau, Gregorio (Institute of Electrical and Electronics Engineers (IEEE), 2018)
      Comunicació de congrés
      Accés obert
      A new outlier-robust approach to estimate the magnitude squared coherence of a random vector sequence, a common task required in a variety of estimation and detection problems, is proposed. The proposed estimator is based ...
    • Robust power allocation algorithms for MIMO OFDM systems with imperfect CSI 

      Rey Micolau, Francesc; Lamarca Orozco, M. Meritxell; Vázquez Grau, Gregorio (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2005-03-31)
      Article
      Accés obert
      This paper presents a Bayesian approach to the design of transmit prefiltering matrices in closed-loop schemes robust to channel estimation errors. The algorithms are derived for a multiple-input multiple-output (MIMO) ...
    • Sampling walls in signal detection of Bernoulli nonuniformly sampled signals 

      Font Segura, Josep; Vázquez Grau, Gregorio; Riba Sagarra, Jaume (2013)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      In this work, we show the existence of sampling walls in signal detection of nonuniformly sampling wideband signals in the presence of noise uncertainty. A sampling wall is the sampling rate below which the target error ...
    • Second-order parameter estimation 

      Villares Piera, Nemesio Javier; Vázquez Grau, Gregorio (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2005-07-31)
      Article
      Accés obert
      This work provides a general framework for the design of second-order blind estimators without adopting any approximation about the observation statistics or the a priori distribution of the parameters. The proposed ...
    • Separation of digital communication signals through joint space-time decorrelation 

      Sala Álvarez, José; Vázquez Grau, Gregorio (1994)
      Text en actes de congrés
      Accés obert
      In this paper we derive the optimum linear algorithm for the separation by an array of a given number of cyclostationary signals of the type encountered in digital communications. Spatially and temporally uncorrelated noise ...
    • Signal selective doa tracking for multiple moving targets 

      Riba Sagarra, Jaume; Goldberg, J; Vázquez Grau, Gregorio; Lagunas Hernandez, Miguel A. (Institute of Electrical and Electronics Engineers (IEEE), 1996)
      Text en actes de congrés
      Accés obert
      A new algorithm for signal selective tracking of the directions-of-arrival (DOAs) of multiple moving targets with an array of passive sensors is presented. A new method based on the principles of maximum likelihood estimation ...
    • Single and multi-frequency wideband spectrum sensing with side-information 

      Font Segura, Josep; Vázquez Grau, Gregorio; Riba Sagarra, Jaume (2014-10-01)
      Article
      Accés obert
      This study addresses the optimal spectrum sensing detection based on the complete or partial side-information on the signal and noise statistics. The use of the generalised-likelihood ratio test (GLRT) involves maximum-likelihood ...
    • Sobre el conocimiento de la densidad espectral de potencia a la entrada, algoritmos adaptativos LMS 

      Lagunas Hernandez, Miguel A.; Vázquez Grau, Gregorio (Fundación Universidad-Empresa, 1986)
      Text en actes de congrés
      Accés obert
    • Specific 2-D spectral estimation for wideband beamforming 

      Lagunas Hernandez, Miguel A.; Vázquez Grau, Gregorio; Sitjar, J F (Institute of Electrical and Electronics Engineers (IEEE), 1990)
      Text en actes de congrés
      Accés obert
    • Sphericity minimum description length: asymptotic performance under unknown noise variance 

      Font Segura, Josep; Riba Sagarra, Jaume; Vázquez Grau, Gregorio (Institute of Electrical and Electronics Engineers (IEEE), 2015)
      Text en actes de congrés
      Accés obert
      This paper revisits the model order selection problem in the context of second-order spectrum sensing in cognitive radio. Taking advantage of the recent interest on the generalized likelihood ratio (GLR), the asymptotic ...
    • Statistical reference criteria for adaptive signal processing in digital communications 

      Sala Álvarez, José; Vázquez Grau, Gregorio (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 1997-01-01)
      Article
      Accés obert
      A general criterion for the design of adaptive systems in digital communications called the statistical reference criterion is proposed. The criterion is based on imposition of the probability density function of the ...
    • Subspace leakage in conventional and dimensionally spread null-space communications 

      Borràs Pino, Jordi; Vázquez Grau, Gregorio (2023-10)
      Article
      Accés obert
      This letter evaluates the impact of subspace leakage in conventional (single-dimension) and dimensionally spread null-space precoding schemes. This phenomenon arises when the null-space inference procedure lacks precision ...
    • System identification through first and second order information from the periodogram 

      Vázquez Grau, Gregorio; Lagunas Hernandez, Miguel A. (Institute of Electrical and Electronics Engineers (IEEE), 1988)
      Text en actes de congrés
      Accés obert
      Email Print Request Permissions The use of first- and second-order information in the characterization of linear systems is considered. Consideration is given to the case when this information is not available but some ...
    • The Gaussian assumption in second-order estimation problems in digital communications 

      Villares Piera, Nemesio Javier; Vázquez Grau, Gregorio (2007-10)
      Article
      Accés obert
      This paper deals with the goodness of the Gaussian assumption when designing second-order blind estimation methods in the context of digital communications. The low- and high-signal-to-noise ratio (SNR) asymptotic performance ...
    • The Gaussian assumption in second-order estimation problems in digital communications 

      Villares Piera, Nemesio Javier; Vázquez Grau, Gregorio (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2007-10-31)
      Article
      Accés obert
      This paper deals with the goodness of the Gaussian assumption when designing second-order blind estimation methods in the context of digital communications. The low- and high-signal-to-noise ratio (SNR) asymptotic ...