Listar GI-GTEC - Artigos por autor "González-Coma, José P."

Mostrando ítems 1-19 de 19

    • 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 ...

    • 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) ...

    • Channel Estimation and Hybrid Precoding for Frequency Selective Multiuser mmWave MIMO Systems 

      González-Coma, José P.; Rodríguez-Fernández, Javier; Gonzalez-Prelcic, Nuria; Castedo, Luis; Heath, Robert W. (IEEE, 2018-05)
      [Abstract]: Configuring the hybrid precoders and combiners in a millimeter wave multiuser multiple-input multiple-output system is challenging in frequency selective channels. In this paper, we develop a system that uses ...

    • Coded Aperture Hyperspectral Image Reconstruction 

      García-Sánchez, Ignacio; Fresnedo, Óscar; González-Coma, José P.; Castedo, Luis (MDPI, 2021)
      [Abstract] In this work, we study and analyze the reconstruction of hyperspectral images that are sampled with a CASSI device. The sensing procedure was modeled with the help of the CS theory, which enabled efficient ...

    • Design of Linear Precoders for Correlated Sources in MIMO Multiple Access Channels 

      Suárez-Casal, Pedro; González-Coma, José P.; Fresnedo, Óscar; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2018-12)
      [Abstract]: This paper focuses on distributed linear precoding when users transmit correlated information over a fading multiple-input and multiple-output multiple access channel. The precoders are optimized in order to ...

    • Evaluation of Analog Joint Source-Channel Coding Systems for Multiple Access Channels 

      Fresnedo, Óscar; González-Coma, José P.; Hassanin, Mohamed; Castedo, Luis; Garcia-Frias, Javier (Institute of Electrical and Electronics Engineers, 2015-06)
      [Abstract]: We address the evaluation of low-complexity analog Joint Source Channel Coding (JSCC) methods for the transmission of discrete-time analog symbols over Multiple-Input Multiple-Output (MIMO) Multiple Access ...

    • FDD Channel Estimation Via Covariance Estimation in Wideband Massive MIMO Systems 

      González-Coma, José P.; Suárez-Casal, Pedro; Castro-Castro, Paula-María; Castedo, Luis (M D P I AG, 2020-02-10)
      [Abstract] A method for channel estimation in wideband massive Multiple-Input Multiple-Output systems using hybrid digital analog architectures is developed. The proposed method is useful for Frequency-Division Duplex at ...

    • Hybrid LISA for Wideband Multiuser Millimeter-Wave Communication Systems Under Beam Squint 

      González-Coma, José P.; Utschick, Wolfgang; Castedo, Luis (IEEE, 2019-02)
      [Abstract]: This paper jointly addresses user scheduling and precoder/combiner design in the downlink of a wideband millimeter-wave communications system. We consider the orthogonal frequency-division multiplexing modulation ...

    • Hybrid Precoding With Time-Modulated Arrays for Mmwave MIMO Systems 

      González-Coma, José P.; Maneiro-Catoira, Roberto; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2018)
      [Abstract]: We consider the utilization of time-modulated arrays (TMAs) as a simple and cost-effective approach to hybrid digital–analog precoding in millimeter wave (mmWave) multiple-input multiple-output (MIMO) systems. ...

    • Intelligent Reflective Surfaces for Wireless Networks: An Overview of Applications, Approached Issues, and Open Problems 

      Pérez-Adán, Darian; Fresnedo, Óscar; González-Coma, José P.; Castedo, Luis (MDPI, 2021)
      [Abstract] An intelligent reflective surface (IRS) is a novel and revolutionizing communication technology destined to enable the control of the radio environment. An IRS is a real-time controllable reflectarray with a ...

    • Low-Complexity Distance-Based Scheduling for Multi-User XL-MIMO Systems 

      González-Coma, José P.; Lopez-Martinez, F.J.; Castedo, Luis (IEEE, 2021-11)
      [Abstract]: We introduce Distance-Based Scheduling (DBS), a new technique for user selection in downlink multi-user communications with extra-large (XL) antenna arrays. DBS categorizes users according to their equivalent ...

    • Performance of MIMO systems in measured indoor channels with transmitter noise 

      Castro-Castro, Paula-María; González-Coma, José P.; García-Naya, José A.; Castedo, Luis (Springer, 2012)
      This study analyzes the impact of transmitter noise on the performance of multiple-input multiple-output (MIMO) systems with linear and nonlinear receivers and precoders. We show that the performance of MIMO linear and ...

    • Power Efficient Scheduling and Hybrid Precoding for Time Modulated Arrays 

      González-Coma, José P.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2020-01-22)
      [Abstract] We consider power efficient scheduling and precoding solutions for multiantenna hybrid digital-analog transmission systems that use Time-Modulated Arrays (TMAs) in the analog domain. TMAs perform beamforming ...

    • QoS constrained power minimization in the MISO broadcast channel with imperfect CSI 

      González-Coma, José P.; Joham, Michael; Castro-Castro, Paula-María; Castedo, Luis (Elsevier, 2017-02)
      [Abstract]: In this paper we consider the design of linear precoders and receivers in a Multiple-Input Single-Output (MISO) Broadcast Channel (BC). We aim to minimize the transmit power while meeting a set of per-user ...

    • QoS constrained power minimization in the multiple stream MIMO broadcast channel 

      González-Coma, José P.; Joham, Michael; Castro-Castro, Paula-María; Castedo, Luis (Elsevier, 2018-02)
      [Abstract]: This work addresses the design of optimal linear transmit filters for the Multiple Input-Multiple Output (MIMO) Broadcast Channel (BC) when several spatial streams are allocated to each user. We further consider ...

    • Rank Constrained Precoding for the Downlink of mmWave Massive MIMO Hybrid Systems 

      González-Coma, José P.; Fresnedo, Óscar; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2021-02-11)
      [Abstract] The hybrid design of precoding schemes for millimeter-wave communications allows exploiting the gains by using large antenna array with an affordable hardware cost and power consumption. In this work, we present ...

    • User Grouping for the Uplink of Multiuser Hybrid mmWave MIMO 

      Pérez-Adán, Darian; Fresnedo, Óscar; González-Coma, José P.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2020-03-16)
      [Abstract] Hybrid analog/digital schemes for precoding/combining have proved to be a low-complexity and/or low-power strategy to obtain reasonable beamforming gains in multiuser millimeter-wave (mmWave) multiple-input ...

    • Wideband Hybrid Precoding Using Time Modulated Arrays 

      González-Coma, José P.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2020-08-05)
      [Abstract] Hybrid digital-analog precoding is a cost effective solution for transmitting over the large bandwidths and huge antenna arrays available in the millimeter wave frequency bands. In this work we focus on the ...

    • Wideband User Grouping for Uplink Multiuser mmWave MIMO Systems With Hybrid Combining 

      Pérez-Adán, Darian; Fresnedo, Óscar; González-Coma, José P.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2021-03-10)
      [Abstract] Analog-digital hybrid precoding and combining schemes constitute an interesting approach to millimeter-wave (mmWave) multiple-input multiple-output (MIMO) systems due to the low hardware complexity and/or low ...