Listar GI-GTEC - Artigos por autor "Castedo, Luis"

Mostrando ítems 1-20 de 79

    • A comparative study of STBC transmissions at 2.4 GHz over indoor channels using a 2 × 2 MIMO testbed 

      Ramírez García, David; Santamaría, Ignacio; Pérez Arriaga, Jesús; Vía, Javier; García-Naya, José A.; Fernández-Caramés, Tiago M.; Pérez-Iglesias, Héctor J.; González-López, Miguel; Castedo, Luis; Torres-Royo, José M. (Hindawi, 2008)
      [Abstract]: In this paper we employ a 2 × 2 Multiple-Input Multiple-Output (MIMO) hardware platform to evaluate, in realistic indoor scenarios, the performance of different space-time block coded (STBC) transmissions at ...

    • A cost-effective IoT system for monitoring Indoor radon gas concentration 

      Blanco, Óscar; Fernández-Caramés, Tiago M.; Fraga-Lamas, Paula; Castedo, Luis (M D P I AG, 2018-07-08)
      [Abstract] Radon is a noble gas originating from the radioactive decay chain of uranium or thorium. Most radon emanates naturally from the soil and from some building materials, so it can be found in many places around the ...

    • A MATLAB Interface for Analyzing Conformal Arrays Composed of Polarized Heterogeneous Elements 

      Brégains, Julio; García-Naya, José A.; González-López, Miguel; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2011-10)
      [Abstract] As an extension and improvement of a previous work, this paper presents a graphical interface designed with MATLAB®, which is capable of representing both the spatial and electrical configurations of a conformal ...

    • A Practical Evaluation of a High-Security Energy-Efficient Gateway for IoT Fog Computing Applications 

      Suárez-Albela, Manuel; Fernández-Caramés, Tiago M.; Fraga-Lamas, Paula; Castedo, Luis (M D P I AG, 2017-08-29)
      [Abstract] Fog computing extends cloud computing to the edge of a network enabling new Internet of Things (IoT) applications and services, which may involve critical data that require privacy and security. In an IoT fog ...

    • A Rank-Constrained Coordinate Ascent Approach to Hybrid Precoding for the Downlink of Wideband Massive (MIMO) Systems 

      González-Coma, José P.; Fresnedo, Óscar; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2023-12)
      [Abstract]: An innovative approach to hybrid analog-digital precoding for the downlink of wideband massive MIMO systems is developed. The proposed solution, termed Rank-Constrained Coordinate Ascent (RCCA), starts seeking ...

    • A Real-Time Implementation of the Mobile WiMAX ARQ and Physical Layer 

      Suárez-Casal, Pedro; Carro Lagoa, Ángel; García-Naya, José A.; Fraga-Lamas, Paula; Castedo, Luis; Morales-Méndez, Antonio (Springer, 2015)
      [Abstract] This paper presents an innovative software-defined radio architecture for the real-time implementation of WiMAX transceivers. The architecture consists of commercially available field-programmable gate array and ...

    • A Review on Internet of Things for Defense and Public Safety 

      Fraga-Lamas, Paula; Fernández-Caramés, Tiago M.; Suárez-Albela, Manuel; Castedo, Luis; González-López, Miguel (Multidisciplinary Digital Publishing Institute, 2016)
      [Abstract], The Internet of Things (IoT) is undeniably transforming the way that organizations communicate and organize everyday businesses and industrial procedures. Its adoption has proven well suited for sectors that ...

    • A TMA-FDA Approach for Two-Beam Steering 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2021)
      [Abstract]: Frequency diverse arrays (FDAs) allow the synthesis of dot-shaped radiated patterns in the range-angle space by applying frequency offsets to the antenna elements. Conventional FDAs are usually implemented with ...

    • A WiMAX Conformal Broad-Beam Antenna 

      Brégains, Julio; Castedo, Luis; Ares Pena, F. J. (Institute of Electrical and Electronics Engineers, 2010-12)
      [Abstract] The numerical model of a very simple conformal antenna, prepared to work in the 3.4 to 3.6 GHz WiMAX range, is presented. The pattern radiated by the proposed antenna displays high gain and excellent linear ...

    • Alternating Minimization for Wideband Multiuser IRS-Aided MIMO Systems Under Imperfect CSI 

      Pérez-Adán, Darian; Joham, Michael; Fresnedo, Óscar; González-Coma, José P.; Castedo, Luis; Utschick, Wolfgang (Institute of Electrical and Electronics Engineers, 2023-11-28)
      [Abstract]: This work focuses on wideband intelligent reflecting surface (IRS)-aided multiuser MIMO systems. One of the major challenges of this scenario is the joint design of the frequency-dependent base station (BS) ...

    • An Electricity Price-Aware Open-Source Smart Socket for the Internet of Energy 

      Blanco, Óscar; Fernández-Caramés, Tiago M.; Fraga-Lamas, Paula; Castedo, Luis (M D P I AG, 2017-03-21)
      [Abstracts] The Internet of Energy (IoE) represents a novel paradigm where electrical power systems work cooperatively with smart devices to increase the visibility of energy consumption and create safer, cleaner and ...

    • Analog Beamforming Using Time-Modulated Arrays With Digitally Preprocessed Rectangular Sequences 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2018-03)
      [Abstract]: Conventional time-modulated arrays are based on the application of variable-width periodical rectangular pulses (easily implemented with radio frequency switches) to the individual antenna excitations. However, ...

    • Analog joint source-channel coding over MIMO channels 

      Vázquez-Araújo, Francisco J.; Fresnedo, Óscar; Castedo, Luis; Garcia-Frias, Javier (SpringerOpen & European Association for Signal Processing, 2014-02)
      [Abstract]: Analog joint source-channel coding (JSCC) is a communication strategy that does not follow the separation principle of conventional digital systems but has been shown to approach the optimal distortion-cost ...

    • Analog Transmission of Correlated Sources Over BC With Distortion Balancing 

      Suárez-Casal, Pedro; Fresnedo, Óscar; Castedo, Luis; Garcia-Frias, Javier (Institute of Electrical and Electronics Engineers, 2017-11)
      [Abstract]: Analog transmission of correlated information over Gaussian broadcast channels (BCs) using analog joint source- channel coding (JSCC) is addressed. This communication strategy has attractive advantages, such ...

    • Analog Transmission of Correlated Sources Over Fading SIMO Multiple Access Channels 

      Suárez-Casal, Pedro; Fresnedo, Óscar; Castedo, Luis; Garcia-Frias, Javier (Institute of Electrical and Electronics Engineers, 2017-07)
      [Abstract]: Joint source-channel coding for discrete-time analog sources is an appealing transmission approach because of its extremely low delay and complexity. When the users access the channel orthogonally, analog ...

    • Analog Transmission of Spatio-Temporal Correlated Sources Over MAC With Modulo Mappings 

      Suárez-Casal, Pedro; Fresnedo, Óscar; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2018-05)
      [Abstract]: Modulo mappings is an appealing scheme for the analog transmission of spatially correlated discrete-time analog source symbols over multiple access channels. In this letter, we show that the modulo mappings are ...

    • Analogue joint source-channel coding for multiple input multiple output–orthogonal frequency division multiplexing systems 

      Fresnedo, Óscar; Vázquez-Araújo, Francisco J.; Castedo, Luis; Garcia-Frias, Javier (Wiley, 2016)
      [Abstract]: Analogue joint source-channel coding (JSCC) has been shown to approach the optimal distortion-cost trade-off when transmitting over additive white Gaussian noise channels. In this work, we consider analogue ...

    • Bit Error Probability and Capacity Bound of OFDM Systems in Deterministic Doubly-Selective Channels 

      Domínguez-Bolaño, Tomás; Rodríguez Piñeiro, José; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2020-10)
      [Abstract]: Doubly-selective channels, such as those that occur when the transmitter and the receiver move relative to each other at high speeds, are a key scenario for fifth generation (5G) cellular systems, which are ...

    • Blind channel identification in Alamouti coded systems: a comparative study of eigendecomposition methods in indoor transmissions at 2.4 GHz 

      Pérez-Iglesias, Héctor J.; García-Naya, José A.; Dapena, Adriana; Castedo, Luis; Zarzoso, Vicente (Wiley, 2008)
      [Abstract]: This paper focuses on blind channel estimation in Alamouti coded systems with one receiving antenna working in indoor scenarios where the flat fading assumption is reasonable. A comparative study of several ...

    • Broadband Access in Complex Environments: LTE on Railway 

      Briso-Rodríguez, Cesar; López, Carlos F.; Fernández, Jean Raphaël Olivier; Pérez Jiménez, Sergio; Draskovic, Drasko; Calle-Sánchez, Jaime; Alonso Montes, José Ignacio; Rodríguez, Carlos; Hernández, Carlos; Molina-García, Mariano; moreno garcia-loygorri, Juan; Rodríguez Piñeiro, José; García-Naya, José A.; Castedo, Luis; Fernandez-Durán, Alfonso (Institute of Electronics, Information and Communication Engineers, 2014)
      [Abstract]: This paper assesses the main challenges associated with the propagation and channel modeling of broadband radio systems in a complex environment of high speed and metropolitan railways. These challenges comprise ...