Exploració per autor "Sala Álvarez, José"Més informacióMés informació

Ara es mostren els items 94-109 de 109

    • On the performance of Hadamard ratio detector-based spectrum sensing for cognitive radios 

      Sedighi, Saeid; Taherpour, Abbas; Sala Álvarez, José; Khattab, Tamer (2015-07-15)
      Article
      Accés obert
      We consider the problem of multiantenna spectrum sensing (SS) in cognitive radios (CRs) when the receivers are assumed to be uncalibrated across the antennas. The performance of the Hadamard Ratio Detector (HRD) is analyzed ...

    • Optimal power control law for equal-rate DS-CDMA networks governed by a successive soft interference cancellation scheme 

      Molina Oliveras, Francesc; Sala Álvarez, José; Villares Piera, Nemesio Javier; Rey Micolau, Francesc (Institute of Electrical and Electronics Engineers (IEEE), 2018)
      Text en actes de congrés
      Accés obert
      This paper studies the throughput maximization of a dense multiple access network of low-rate subscribers that share the same practical Forward Error Correction (FEC) code and modulation scheme, and transmit to a central ...

    • Optimum energy allocation for massive spread-spectrum multiple access in networks of uncoordinated energy-limited terminals 

      Villares Piera, Nemesio Javier; Rey Micolau, Francesc; Sala Álvarez, José (Institute of Electrical and Electronics Engineers (IEEE), 2016)
      Text en actes de congrés
      Accés obert
      This paper derives the energy allocation policy that maximizes the aggregate spectral efficiency of an uncoordinated spread-spectrum multiple access network operating in the large-user regime and subject to a longterm ...

    • Proyecto AVANT. Estudio de técnicas de sincronización para relaciones señal a ruido muy bajas. D11: Disseny del codificador i descodificador del turbo-codi de l'estàndard DVB-RCS 

      Lamarca Orozco, M. Meritxell; Ramírez Javega, Francisco; Rey Micolau, Francesc; Riba Sagarra, Jaume; Sala Álvarez, José; Vázquez Grau, Gregorio; Villares Piera, Nemesio Javier (2010-07-16)
      Report de recerca
      Accés restringit per acord de confidencialitat
      This document contains the instructions for the design of the DVB-RCS turbo-code. Both the algorithmic and implementation issues are addressed in the document.

    • Proyecto AVANT. Estudio de técnicas de sincronización para relaciones señal a ruido muy bajas. D12. Disseny i simulació dels algorismes de sincronització 

      Villares Piera, Nemesio Javier; Font Segura, Josep; Lamarca Orozco, M. Meritxell; Matas Navarro, David; Ramírez Javega, Francisco; Rey Micolau, Francesc; Riba Sagarra, Jaume; Sala Álvarez, José; Vázquez Grau, Gregorio (2010-07-16)
      Report de recerca
      Accés restringit per acord de confidencialitat
      In this document, the synchronization algorithms developed during the project are presented and simulated. The studied algorithms are designed for a QS-CDMA system operating in the low SNR regime, i.e., at low Es/No values ...

    • Pulsar navigation 

      Sala Álvarez, José; Urruela Planas, Andreu; Villares Piera, Nemesio Javier; Romeu Robert, Jordi; Blanch Boris, Sebastián; Estalella Boadella, Robert; Paredes, J. M. (European Space Agency (ESA), 2008-12-31)
      Article
      Accés restringit per política de l'editorial
      This paper evaluates the fundamental performance bounds, signal processing and technological complexity associated with the synchronization to radio and X-ray pulsars as well as its impact on the positioning accuracy of ...

    • Rate allocation in massive multiple access combining successive decoding with error control 

      Molina Oliveras, Francesc; Sala Álvarez, José (Institute of Electrical and Electronics Engineers (IEEE), 2021)
      Text en actes de congrés
      Accés obert
      The Gaussian multiple access channel under asymptotically many code-division-multiple-access users and successive interference cancellation (SIC) is investigated in this work. Users transmit n-symbol packets and select ...

    • Regions de decisió i cota de la unió 

      Sala Álvarez, José (2018-10-01)
      Report de recerca
      Accés obert
      Aquest document presenta de forma gràfica: - La determinació de la regió de decisió R associada a un símbol complexe s = I + jQ . - La determinació de la seva probabilitat d’error i la d’una cot a superior (Cota de la ...

    • SENYALS I SISTEMES (Examen 2n Quadr.) 

      Sala Álvarez, José (Universitat Politècnica de Catalunya, 2002-04-01)
      Examen
      Accés restringit a la comunitat UPC

    • SENYALS I SISTEMES (Examen 2n Quadr.) 

      Sala Álvarez, José (Universitat Politècnica de Catalunya, 2002-06-01)
      Examen
      Accés restringit a la comunitat UPC

    • 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 ...

    • Sidelobe suppression for multicarrier signals via structured spectral precoding 

      Hussain, Khawar; López Valcarce, Roberto; Rey Micolau, Francesc; Sala Álvarez, José; Villares Piera, Nemesio Javier (Institute of Electrical and Electronics Engineers (IEEE), 2024-01-22)
      Article
      Accés obert
      Reducing the large sidelobes of multicarrier signals is crucial to prevent adjacent channel interference. Spectral precoding is an effective approach toward this goal, at the expense of throughput loss due to precoder ...

    • SINR profile for spectral efficiency optimization of SIC receivers in the many-user regime 

      Sala Álvarez, José; Villares Piera, Nemesio Javier; Rey Micolau, Francesc (Institute of Electrical and Electronics Engineers (IEEE), 2015)
      Comunicació de congrés
      Accés obert
      In dense wireless scenarios, and particularly under high traffic loads, the design of efficient random access protocols is necessary. Some candidate solutions are based on Direct- Sequence Spread Spectrum ...

    • Spectrum sensing using correlated receiving multiple antennas in cognitive radios 

      Sedighi, Saeid; Taherpour, Abbas; Sala Álvarez, José (2013-11)
      Article
      Accés restringit per política de l'editorial
      Spectrum sensing is a key component for enabling the cognitive radio paradigm. In this paper, we propose a novel totally-blind spectrum sensing technique for cognitive radio device equipped with multiple antennas, namely ...

    • 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 ...

    • Stochastic dynamic models in PHY abstraction 

      Rey Micolau, Francesc; Sala Álvarez, José (Institute of Electrical and Electronics Engineers (IEEE), 2013)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      Physical Layer (PHY) abstraction aims to model link performance and accelerate system-level analyses of communication systems by reducing simulation complexity and their associated computational costs. We examine a Physical ...