Listar GI-GTEC - Artigos por autor "García-Naya, José A."

Mostrando ítems 21-40 de 62

    • Detection of channel variations to improve channel estimation methods 

      Dapena, Adriana; Castro-Castro, Paula-María; García-Naya, José A.; Zarzoso, Vicente (Springer, 2014-08)
      [Abstract] In current digital communication systems, channel information is typically acquired by supervised approaches that use pilot symbols included in the transmit frames. Given that pilot symbols do not convey user ...

    • Direct Antenna Frequency-Hopped M-FSK Modulation With Time-Modulated Arrays 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2024-02)
      [Abstract]: We present an innovative approach that simultaneously enables direct antenna frequency-hopped M-ary frequency shift keying (DAFH-MFSK) modulation and beamsteering through the use of time-modulated arrays (TMAs). ...

    • Dual-Beam Steerable TMAs Combining AM and PM Switched Time-Modulation 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (MDPI, 2022)
      [Abstract] Wireless sensor networks (WSN) are increasingly requiring directional antennas that not only provide higher capacity, security, transmission range or robustness against interference, but also contribute with ...

    • Dual-Signal Transmission Using RF Precoding and Analog Beamforming With TMAs 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (IEEE, 2018-06)
      [Absctract]: Time-modulated arrays (TMAs) receiving beamforming provide a noteworthy hardware simplicity given the ability of this multi-antenna technique to transform spatial diversity into frequency diversity. However, ...

    • Dual-Signal Transmission Using RF Precoding and Analog Beamforming With TMAs 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2018)
      [Abstract]: Time-modulated arrays (TMAs) receiving beamforming provide a noteworthy hardware simplicity given the ability of this multi-antenna technique to transform spatial diversity into frequency diversity. However, ...

    • Emulating extreme velocities of mobile LTE receivers in the downlink 

      Rodríguez Piñeiro, José; Lerch, Martin; García-Naya, José A.; Caban, Sebastian; Rupp, Markus; Castedo, Luis (SpringerOpen & European Association for Signal Processing, 2015)
      [Abstract]: Long-Term Evolution (LTE) is expected to substitute the Global System for Mobile (GSM) Communications as the radio access technology for railway communications. Recently, considerable attention has been devoted ...

    • Enhanced Time-Modulated Arrays for Harmonic Beamforming 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2017)
      [Abstract]: One of the primary features of time-modulated arrays (TMAs) is their ability to adapt their harmonic patterns to exploit the angular diversity of multipath wireless channels. In such a case, the TMA excitations ...

    • Environmental Cross-Validation of NLOS Machine Learning Classification/Mitigation with Low-Cost UWB Positioning Systems 

      Barral Vales, Valentín; Escudero, Carlos J.; García-Naya, José A.; Suárez-Casal, Pedro (M D P I AG, 2019-12-10)
      [Abstract] Indoor positioning systems based on radio frequency inherently present multipath-related phenomena. This causes ranging systems such as ultra-wideband (UWB) to lose accuracy when detecting secondary propagation ...

    • Equalizers in mobile communications: Tutorial 38 

      Rupp, Markus; García-Naya, José A. (Institute of Electrical and Electronics Engineers & Instrumentation and Measurement Society, 2012-06)
      [Abstract]: Modern cellular wireless systems would not be possible without high-performance equalizers. Signal impairments introduced by the wireless channel can only be compensated for by using such equalizers. This ...

    • Evaluation of H.264/AVC over IEEE 802.11p vehicular networks 

      Rozas-Ramallal, Ismael; Fernández-Caramés, Tiago M.; Dapena, Adriana; García-Naya, José A. (SpringerOpen & European Association for Signal Processing, 2013)
      [Abstract]: The capacity of vehicular networks to offer non-safety services, like infotainment applications or the exchange of multimedia information between vehicles, have attracted a great deal of attention to the field ...

    • Experimental Characterization of LTE Wireless Links in High-Speed Trains 

      Domínguez-Bolaño, Tomás; Rodríguez Piñeiro, José; García-Naya, José A.; Castedo, Luis (Hindawi, 2017)
      [Abstract]: Multimedia and data-based services experienced a nonstopping growth over the last few years. People are continuously on the move using devices to access multimedia contents or other data-based services. Due to ...

    • Experimental evaluation in wireless communications 

      García-Naya, José A.; Heath, Robert W.; Kaltenberger, Florian; Rupp, Markus; Vía, Javier (SpringerOpen & European Association for Signal Processing, 2017)
      [Abstract]: This editorial sums up relevant topics on the assessment of wireless communication systems covered by the especial issue entitled “Experimental Evaluation in Wireless Communications.” The topics include practical ...

    • Experimental Evaluation of Flexible Duplexing in Multi-Tier MIMO Networks 

      Fanjul, Jacobo; Fernández, Renzo D.; Ibáñez, Jesús; García-Naya, José A.; Santamaría, Ignacio (SpringerOpen, 2020-09-24)
      [Abstract] In this paper, we present an experimental evaluation of the performance benefits provided by flexible duplexing, an access technique that allows uplink and downlink cells to coexist within the same time-frequency ...

    • Experimental evaluation of interference alignment for broadband WLAN systems 

      Lameiro, Christian; González Fernández, Óscar; García-Naya, José A.; Santamaría, Ignacio; Castedo, Luis (SpringerOpen & European Association for Signal Processing, 2015)
      [Abstract]: In this paper, we present an experimental study on the performance of spatial interference alignment (IA) in indoor wireless local area network scenarios that use orthogonal frequency division multiplexing ...

    • Experimental evaluation of the WiMAX downlink physical layer in high-mobility scenarios 

      Suárez-Casal, Pedro; Rodríguez Piñeiro, José; García-Naya, José A.; Castedo, Luis (SpringerOpen & European Association for Signal Processing, 2015)
      [Abstract]: The experimental evaluation of the WiMAX downlink physical layer in high-mobility scenarios is extremely difficult to carry out because it requires the realization of measurement campaigns with expensive ...

    • Fine Time Measurement for the Internet of Things: A Practical Approach Using ESP32 

      Barral Vales, Valentín; Campos Fernández, Omar; Domínguez-Bolaño, Tomás; Escudero, Carlos J.; García-Naya, José A. (Institute of Electrical and Electronics Engineers Inc. (IEEE), 2022)
      [Abstract]: In the world of Internet of Things (IoT), obtaining the physical location of devices has always been a task of great interest for developing increasingly complex location-based services (LBS). That is why in ...

    • Hybrid Channel Estimation Strategy for MIMO Systems with Decision Feedback Equalizer 

      Pérez-Iglesias, Héctor J.; Dapena, Adriana; Castro-Castro, Paula-María; García-Naya, José A. (Springer, 2010)
      [Abstract] We propose to combine supervised and unsupervised algorithms in order to improve the performance of multiple-input multiple-output digital communication systems which make use of differential feedback equalizers ...

    • Hybrid Supervised-Unsupervised Channel Estimation Scheme with Dynamic Transmission of Pilots 

      Dapena, Adriana; Castro-Castro, Paula-María; García-Naya, José A. (Springer, 2011-02)
      [Abstract] Multiple-Input Multiple-Output (MIMO) digital communications standards typically include pilot symbols in the definition of the transmit signals with the purpose of acquiring the Channel State Information (CSI) ...

    • Impact of Time-Modulated Arrays on the BER of Linear Digital Modulations 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Taylor & Francis, 2015-08-21)
      [Abstract] Time modulation provides a simple way to control the power radiation pattern of an antenna array. By appropriately selecting the parameters of a Time-Modulated Array (TMA) it is possible to obtain a reconfigurable ...

    • Interference Alignment Testbeds 

      Yetis, Cenk M.; Fanjul, Jacobo; García-Naya, José A.; Moghadam, Nima N.; Farhadi, Hamed (Institute of Electrical and Electronics Engineers, 2017)
      [Abstract]: Interference alignment has triggered high impact research in wireless communications since it was proposed nearly 10 years ago. However, the vast majority of research is centered on the theory of interference ...