Enviaments recents

  • A new positive time-frequency distribution 

    Rodríguez Fonollosa, Javier; Nikias, C L (1994)
    Text en actes de congrés
    Accés obert
    This article studies the formulation of new members of the Cohen-Posch (1985) class of positive time-frequency energy distributions. Members of this class are always positive functionals and satisfy the marginal constraints. ...
  • Diversity mdir receiver for space-time dispersive channels 

    Vidal Manzano, José; Cabrera Beán, Margarita Asuncion; Agustin, Adrian; Lagunas Hernandez, Miguel A. (European Commission, 2000)
    Text en actes de congrés
    Accés obert
    A particular property of the cellebrated MDIR receiver is introduced in this communication, namely, the fact that full exploitation of the diversity is obtained with multiple beamformers when the channel is spatially and ...
  • Joint beamforming and channel estimation for pilot-aided WCDMA systems 

    Mestre Pons, Francesc X.; Nájar Martón, Montserrat; Rodríguez Fonollosa, Javier (Institute of Electrical and Electronics Engineers (IEEE), 2000)
    Text en actes de congrés
    Accés obert
    The problem of joint beamforming and channel estimation for multi-rate multi-code systems is addressed. Usual schemes perform this filtering/estimation operation making use of a training sequence time-multiplexed with the ...
  • Joint synchronization and symbol detection in asynchronous DS-CDMA systems 

    Rey Micolau, Francesc; Vázquez Grau, Gregorio; Riba Sagarra, Jaume (Institute of Electrical and Electronics Engineers (IEEE), 2000)
    Text en actes de congrés
    Accés obert
    The design of accurate estimators which also consider the noise term in low SNR scenarios is paramount for achieving optimal solutions and obtaining precise symbol detectors. Particularly, this paper estimates the propagation ...
  • Space-time coding for UMTS. Performance evaluation in combination with convolutional and turbo coding 

    Gaspa Maynou, Roger; Rodríguez Fonollosa, Javier (Institute of Electrical and Electronics Engineers (IEEE), 2000)
    Text en actes de congrés
    Accés obert
    Space-time codes provide both diversity and coding gain when using multiple transmit antennas to increase spectral efficiency over wireless communications systems. Space-time block codes have already been included in the ...
  • A reduced-complexity and asymptotically efficient time-delay estimator 

    Seco Granados, Gonzalo; Swindlehurst, A L; Fernández Rubio, Juan Antonio; Astély, D (ICASSP, 2000)
    Text en actes de congrés
    Accés obert
    This paper considers the problem of estimating the time delays of multiple replicas of a known signal received by an array of antennas. Under the assumptions that the noise and co-channel interference (CCI) are spatially ...
  • Time-delay estimation of the line-of-sight signal in a multipath environment 

    Seco Granados, Gonzalo; Fernández Rubio, Juan Antonio (EUSIPCO, 2000)
    Text en actes de congrés
    Accés obert
    The problem of estimating the time-delay of the line-of-sight (LOSS) or direct signal received by an antenna array in a multipath scenario is addressed. This problem is essential in many communication, radar, sonar and ...
  • Non-data-aided frequency offset and symbol timing estimation for binary CPM: performance bounds 

    Riba Sagarra, Jaume; Vázquez Grau, Gregorio (Institute of Electrical and Electronics Engineers (IEEE), 2000)
    Text en actes de congrés
    Accés obert
    The use of (spectrally efficient) CPM modulations may lead to a serious performance degradation of the classical non-data-aided (NDA) frequency and timing estimators due to the presence of self noise. The actual performance ...
  • Pilot-aided ML schemes for joint beamforming and channel estimation in WCDMA systems 

    Mestre Pons, Francesc X.; Rodríguez Fonollosa, Javier (Institute of Electrical and Electronics Engineers (IEEE), 2000)
    Text en actes de congrés
    Accés obert
    This paper proposes semi-blind channel estimation and interference cancellation schemes for the reception of pilot-aided signals in WCDMA systems. It is shown that the performance of classical training-based schemes is ...
  • Data hidding in color images using perceptual models 

    Vidal Manzano, José; Sayrol Clols, Elisa; Madueño Ruíz, María Isabel (Christian Germain, Eric Grivel, Olivier Lavialle, 2000)
    Text en actes de congrés
    Accés obert
    One of the problems arising from the use of digital media is the ease of identical copies of digital images or audio files, allowing manipulation and unauthorized use. Copyright is an effective tool for preserving ...

Mostra'n més