Now showing items 1-20 of 54

  • Adaptive array beamforming for frequency hopping modulation 

    Nájar Martón, Montserrat; Lagunas Hernandez, Miguel A. (1996)
    Conference report
    Open Access
    A new architecture for Array Processing using Frequency Hopping (FH) modulation is addressed in this paper which takes advantage of the knowledge of the frequency sequence at the receiver, requiring neither temporal nor ...
  • Adaptive Beamforming for High Bit Rate Services in the FDD Mode of UTRA 

    Mestre Pons, Francesc X.; Nájar Martón, Montserrat; Antón Haro, Carles; Rodríguez Fonollosa, Javier (Institute of Electrical and Electronics Engineers (IEEE), 1999)
    Conference report
    Open Access
    Most time-reference beamforming algorithms suffer from severe beampattern distortion effects when applied to high bit rate services in WCDMA, causing serious performance degradation in terms of output BER, especially at ...
  • Assessment of direct positioning for IR-UWB in IEEE 802.15.4a channels 

    Navarro, Mònica; Closas, Pau; Nájar Martón, Montserrat (Institute of Electrical and Electronics Engineers (IEEE), 2013)
    Conference report
    Restricted access - publisher's policy
    This paper assesses the problem of localization in IR-UWB under realistic channel models for Direct Position Estimation (DPE) approaches. DPE schemes have been proposed for positioning and localization for well developed ...
  • Asymptotically optimal linear shrinkage of sample LMMSE and MVDR filters 

    Serra, Jordi; Nájar Martón, Montserrat (2014-07-15)
    Article
    Restricted access - publisher's policy
    Conventional implementations of the linearminimum mean-square (LMMSE) and minimum variance distortionless response (MVDR) estimators rely on the sample matrix inversion (SMI) technique, i.e., on the sample covariance matrix ...
  • Blind wideband source separation 

    Nájar Martón, Montserrat; Lagunas Hernandez, Miguel A.; Bonet, I (1994)
    Conference report
    Open Access
    This paper deals with the general problem of separating two independent wideband sources when they are mixed by unknown filters. In order to solve this problem, a backward framework is proposed which is composed of two ...
  • Casting signal processing to reall-world data 

    Closas Gómez, Pau; Conti, Andrea; Dardari, Davide; Decarli, Nicoló; Falletti, Emanuela; Fernández Prades, Carlos; Gholami, Mohammad Reza; Nájar Martón, Montserrat; Lagunas Targarona, Eva; Pini, Marco; Rydström, Mats; Sottile, Francesco; Ström, Erik G. (Elsevier, 2011-10)
    Part of book or chapter of book
    Restricted access - publisher's policy
    This chapter presents the results of a testing and validation activity carried out to analyze the performance of signal-processing techniques related to positioning and navigation. The steps included the setup of a measurement ...
  • Compressed spectrum sensing in the presence of interference: comparison of sparse recovery strategies 

    Lagunas Targarona, Eva; Nájar Martón, Montserrat (Institute of Electrical and Electronics Engineers (IEEE), 2014)
    Conference report
    Restricted access - publisher's policy
    Existing approaches to Compressive Sensing (CS) of sparse spectrum has thus far assumed models contaminated with noise (either bounded noise or Gaussian with known power). In practical Cognitive Radio (CR) networks, primary ...
  • Compressive sensing for through wall radar imaging of stationary scenes using arbitrary data measurements 

    Lagunas Targarona, Eva; Amin, Moeness G.; Ahmad, Fauzia; Nájar Martón, Montserrat (2012)
    Conference report
    Restricted access - publisher's policy
    In this paper, we deal with removal of wall EM reflections prior to image reconstruction using step-frequency radars. The goal is to enable behind-the-wall target detection and localization from reduced data measurements. ...
  • Compressive spectrum sensing based on spectral shape feature detection 

    Lagunas, Eva; Nájar Martón, Montserrat (Institute of Electrical and Electronics Engineers (IEEE), 2013)
    Conference report
    Restricted access - publisher's policy
    In this paper, we address sparsity-based spectrum sensing for Cognitive Radio (CR) applications. Motivated by the sparsity described by the low spectral occupancy of the licensed radios, the proposed approach utilizes the ...
  • Cramer-rao bound for time-delay estimation in the frequency domain 

    Serra, Jordi; Blanco, Luis; Nájar Martón, Montserrat (European Association for Signal Processing (EURASIP), 2009)
    Conference report
    Restricted access - publisher's policy
    In this paper a measure of performance of time delay estimators arising from a frequency model of the received signal is presented. The aim is to derive theoretical analysis of the Cramer-Rao bound (CRB) for time delay ...
  • Determining building interior structures using compressive sensing 

    Lagunas Targarona, Eva; Amin, Moeness; Ahmad, Fauzia; Nájar Martón, Montserrat (2013-01-22)
    Article
    Open Access
    We consider imaging of the building interior structures using Compressive Sensing (CS) with applications to through-the-wall imaging and urban sensing. We consider a monostatic synthetic aperture radar imaging system ...
  • Double shrinkage correction in sample LMMSE estimation 

    Serra, Jordi; Nájar Martón, Montserrat (European Association for Signal Processing (EURASIP), 2013)
    Conference report
    Restricted access - publisher's policy
    The sample linear minimum mean square error (LMMSE) es- timator undergoes high performance degradation in the small sample size regime. Herein a double shrinkage correction is proposed to alleviate this problem. First, ...
  • Energy efficiency communications over the AWGN relay channel 

    Gómez Vilardebó, Jesús; Pérez Neira, Ana Isabel; Nájar Martón, Montserrat (2010)
    Article
    Restricted access - publisher's policy
    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
    Open Access
    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 ...
  • Filter bank transceiver design for ultra wideband 

    Ibars, C.; Navarro, Mònica; Fernández Prades, Carlos; Artiga, Xavier; Moragrega, Ana; George-Gavrincea, Ciprian; Mollfulleda, Antonio; Nájar Martón, Montserrat (Sciyo.com, 2010-09)
    Part of book or chapter of book
    Open Access
  • Frequency domain joint TOA and DOA estimation in IR-UWB 

    Navarro, M; Nájar Martón, Montserrat (2011-10)
    Article
    Restricted access - publisher's policy
    This paper addresses the problem of TOA and DOA estimation in IR-UWB systems. It considers a frequency domain approach for joint high resolution estimation of Time Of Arrival (TOA) and Direction Of Arrival (DOA). The ...
  • Fundamental limits in the accuracy of wireless positioning 

    Bacci, Giacomo; Closas Gómez, Pau; D'Amico, Antonio; Dardari, Davide; Fernández Prades, Carlos; Fontanella, Diana; Gezici, Sinan; Luise, Marco; Mallat, Achraf; Mengali, Umberto; Nájar Martón, Montserrat; Nicoli, Monica; Oestges, Claude; Vandendorpe, Luc (Elsevier, 2011-10)
    Part of book or chapter of book
    Restricted access - publisher's policy
  • Gestión inteligente de los recursos radio para redes Ad-hoc de alta velocidad a través del desarrollo de técnicas de lógica Fuzzy, procesado de señal y protocolos de acceso al medio 

    Pérez Neira, Ana Isabel; Pascual Iserte, Antonio; Nájar Martón, Montserrat (2005)
    Conference report
    Open Access
    The general goal of Girafa is to increase throughput and quality of service (QoS) in ad-hoc networks by applying strategies of reconfigurability and PHY/MAC cross-layer design and by developing techniques involving fuzzy ...
  • High resolution adaptative arrays based on random processing techniques: frequency hopping modulation 

    Nájar Martón, Montserrat; Lagunas Hernandez, Miguel A. (Institute of Electrical and Electronics Engineers (IEEE), 1995)
    Conference report
    Open Access
    A new architecture for adaptive arrays using frequency hopping modulation is addressed. The resolution of the array and the interference rejection increase substantially applying random processing to the carrier frequency ...
  • High resolution adaptive arrays based on random processing techniques: frequency hopping modulation 

    Nájar Martón, Montserrat; Lagunas Hernandez, Miguel A. (Institute of Electrical and Electronics Engineers (IEEE), 1995)
    Conference report
    Open Access
    A new architecture for adaptive arrays using frequency hopping modulation is addressed. The resolution of the array and the interference rejection increase substantially applying random processing to the carrier frequency ...