Now showing items 21-40 of 105

  • Bit-slice implementation of a linear predictive vocoder 

    Vázquez Grau, Gregorio; Gasull Llampallas, Antoni (1985)
    Conference report
    Open Access
    A digital 16-bit high-speed general-purpose signal-processor is shown. The main objective has been the implementation of a linear predictive vocoder for obtaining real-time speech compression. For real-time digital speech ...
  • Blind equalization based on spatial and temporal diversity in block coded modulations 

    Rey Micolau, Francesc; Lamarca Orozco, M. Meritxell; Vázquez Grau, Gregorio (Institute of Electrical and Electronics Engineers (IEEE), 1998)
    Conference report
    Open Access
    Linear block codes can be applied in spatial and/or temporal diversity receivers in order to develop high performance schemes for blind equalization in mobile communications. The proposed technique uses the structure of ...
  • Blind equalization of DS-CDMA and MC-CDMA modulations in time-variant frequency selective channels 

    Rey Micolau, Francesc; Vázquez Grau, Gregorio (Institute of Electrical and Electronics Engineers (IEEE), 1999)
    Conference report
    Open Access
    The paper addresses the blind equalization problem of spread spectrum modulations in the presence of fast time-variant frequency-selective channels. The basic assumption of the paper is that the channel response exhibits ...
  • Channel estimation for transform modulations in mobile communications 

    Lamarca Orozco, M. Meritxell; Vázquez Grau, Gregorio (1996)
    Conference report
    Open Access
    This paper deals with data-aided channel estimation in systems using OFDM modulation. We formulate a pilot symbol-based channel estimator and compare it with the pilot-tone one proposed in [1]. Although this paper focuses ...
  • Compressed correlation-matching for spectrum sensing in sparse wideband regimes 

    Font Segura, Josep; Vázquez Grau, Gregorio; Riba Sagarra, Jaume (IEEE Press. Institute of Electrical and Electronics Engineers, 2011)
    Conference lecture
    Restricted access - publisher's policy
    In this paper, we consider a novel compressed correlation-matching (CCM) approach for spectrum sensing of wideband sparse signals. We derive a general closed-form estimate of the wideband sparse signal level from compressed ...
  • Conditional maximum likelihood frequency estimation for staggered modulations 

    Riba Sagarra, Jaume; Vázquez Grau, Gregorio (1998)
    Conference report
    Open Access
    The use of spectrally efficient continuous phase modulations for mobile communications may lead to a serious performance degradation of the classical frequency error detectors (FEDs) due to the presence of self-noise. This ...
  • Conditional maximum likelihood timing recovery 

    Riba Sagarra, Jaume; Vázquez Grau, Gregorio (Institute of Electrical and Electronics Engineers (IEEE), 1999)
    Conference report
    Open Access
    The conditional maximum likelihood (CML) principle, well known in the context of sensor array processing, is applied to the problem of timing recovery. A new self-noise free CML-based timing error detector is derived. ...
  • Conditional maximum likelihood timing recovery: estimators and bounds 

    Riba Sagarra, Jaume; Sala i Álvarez, Josep; Vázquez Grau, Gregorio (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2001-04-30)
    Article
    Open Access
    This paper is concerned with the derivation of new estimators and performance bounds for the problem of timing estimation of (linearly) digitally modulated signals. The conditional maximum likelihood (CML) method is adopted, ...
  • Constant variance transversal filtering for adaptive channel equalization 

    Vázquez Grau, Gregorio; Gasull Llampallas, Antoni; Sanchez, J J; Lagunas Hernandez, Miguel A. (1989)
    Conference report
    Open Access
  • D1. Estudio de códigos PN para mejorar el ensanchado y la eficiencia espectral del sistema CDMA síncrono y asíncrono 

    Lamarca Orozco, M. Meritxell; Rey Micolau, Francesc; Riba Sagarra, Jaume; Sala Álvarez, José; Vázquez Grau, Gregorio; Villares Piera, Nemesio Javier (2008-11-10)
    External research report
    Restricted access - confidentiality agreement
  • D2. Estructuras de detector multiusuario para CDMA síncrono y asíncrono 

    Lamarca Orozco, M. Meritxell; Rey Micolau, Francesc; Riba Sagarra, Jaume; Sala Álvarez, José; Vázquez Grau, Gregorio; Villares Piera, Nemesio Javier (2008-11-10)
    External research report
    Restricted access - confidentiality agreement
  • D3. Sincronización robusta de frecuencia y fase para M-PSK sobre CDMA 

    Lamarca Orozco, M. Meritxell; Rey Micolau, Francesc; Riba Sagarra, Jaume; Sala Álvarez, José; Vázquez Grau, Gregorio; Villares Piera, Nemesio Javier (2008-11-10)
    External research report
    Restricted access - confidentiality agreement
  • DA-GLRT burst detection and synchronization based on a chirp-like preamble 

    Rodríguez, E; Lamarca Orozco, M. Meritxell; López Salcedo, José Antonio; Rey Micolau, Francesc; Riba Sagarra, Jaume; Sala Álvarez, José; Vázquez Grau, Gregorio; Villares Piera, Nemesio Javier; Jalón, A (2008)
    Conference report
    Restricted access - publisher's policy
    A specific preamble for the tasks of signal detection and synchronization in burst digital communications is presented. The preamble resembles a chirp signal used in RADAR applications. Its main benefit is that it allows ...
  • Data-dependent error weighting for constant variance transversal filtering 

    Vázquez Grau, Gregorio (Elsevier, 1990)
    Conference report
    Open Access
  • Data pre-processing for high-resolution adaptive algorithms 

    Vázquez Grau, Gregorio; Gasull Llampallas, Antoni (Institute of Electrical and Electronics Engineers (IEEE), 1988)
    Conference report
    Open Access
    The inclusion of adaptive methods in high-resolution spectral estimation algorithms is considered. The generation of a complete family of spectral estimators from the normalized maximum-likelihood method (MLM) is discussed. ...
  • Data pre-processing for high-resolution adaptive algorithms 

    Vázquez Grau, Gregorio; Gasull Llampallas, Antoni (Institute of Electrical and Electronics Engineers (IEEE), 1988)
    Conference report
    Open Access
    The inclusion of adaptive methods in high-resolution spectral estimation algorithms is considered. The generation of a complete family of spectral estimators from the normalized maximum-likelihood method (MLM) is discussed. ...
  • Descripciones tiempo-frecuencia en la recuperacion conjunta de param 

    Riba Sagarra, Jaume; Vázquez Grau, Gregorio (Universidad de Málaga, 1992)
    Conference report
    Open Access
  • Design and implementation of a 2048FFT capture spectrum analyzer 

    Vázquez Grau, Gregorio (1985)
    Conference report
    Open Access
    This paper describes the hardware implementation of a digital spectrum analyzer which, by using a capture process of the signal under processing, performs some non parametric signal processing techniques. All the possibilities ...
  • Detection of PPM-UWB random signals 

    López Salcedo, José Antonio; Vázquez Grau, Gregorio (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2008-04-23)
    Article
    Open Access
    This paper focuses on the symbol detection problem of random pulse-position modulation (PPM) ultrawideband (UWB) signals in the absence of interframe interference. Particular attention is devoted to severely time-varying ...
  • Detectores duales de frecuencia dependientes de los datos en comunicaciones digitales 

    Lamarca Orozco, M. Meritxell; Vázquez Grau, Gregorio (Universidad de Málaga, 1992)
    Conference report
    Open Access