Carlos A. Gutierrez

Dr. Carlos A. Gutierrez

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Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 January 2017 in IEEE Transactions on Wireless Communications
Verified
Journal Article
Closed access
WDWiem Dahech
Wiem Dahech
MPMatthias Uwe Pätzold
Matthias Uwe Pätzold
CGCarlos A. Gutierrez
Carlos A. Gutierrez
NYNeji Youssef
Neji Youssef
In mobile-to-mobile (M2M) communication systems, both the transmitter and the receiver are moving with a certain velocity, which is usually assumed to be constant over time. However, in realistic propagation scenarios, the velocity of the mobile stations (MSs) is subject to changes resulting in a non-stationary fading process. In this paper, we develop a non-stationary narrow-band M2M multipath fading channel model, where the transmitter and the receiver experience changes in their velocities and trajectories. For this model, we derive expressions for the local autocorrelation function (ACF), the Wigner-Ville spectrum, the local average Doppler shift, and the local Doppler spread under isotropic scattering conditions. In addition, we investigate the correlation properties of the proposed model assuming non-isotropic scattering around the MSs. By relaxing the standard assumption of constant velocities of the MSs, this paper shows that the local ACF and the Wigner-Ville spectrum differ completely from known expressions derived for wide-sense stationary M2M channel models. Furthermore, it is shown that our model provides consistent results with respect to the Doppler spread. The proposed channel model is useful for the performance analysis of M2M communication systems under non-stationary conditions caused by velocity variations of the MSs.
10 August 2017 in IEEE Transactions on Vehicular Technology
Verified
Journal Article
Closed access
CGCarlos A. Gutierrez
Carlos A. Gutierrez
JGJose T. Gutierrez-Mena
Jose T. Gutierrez-Mena
JLJ.M Luna-Rivera
J.M Luna-Rivera
Daniel Ulises Campos-DelgadoDaniel Ulises Campos-Delgado
Daniel Ulises Campos-Delgado
Ramiro VelazquezRamiro Velazquez
Ramiro Velazquez
MPMatthias Uwe Pätzold
Matthias Uwe Pätzold
In this paper, we present a novel geometry-based statistical model for small-scale non-wide-sense stationary uncorrelated scattering (non-WSSUS) mobile-to-mobile (M2M) Rayleigh fading channels. The proposed model builds on the principles of plane wave propagation to capture the temporal evolution of the propagation delay and Doppler shift of the received multipath signal. This is different from existing non-WSSUS geometry-based statistical channel models, which are based on a spherical wave propagation approach, that in spite of being more realistic is more mathematically intricate. By considering an arbitrary geometrical configuration of the propagation area, we derive general expressions for the most important statistical quantities of nonstationary channels, such as the first-order probability density functions of the envelope and phase, the four-dimensional (4-D) time-frequency correlation function (TF-CF), local scattering function (LSF), and time-frequency-dependent delay and Doppler profiles. We also present an approximate closed-form expression of the channel's 4-D TF-CF for the particular case of the geometrical one-ring scattering model. The obtained results provide new theoretical insights into the correlation and spectral properties of non-WSSUS M2M Rayleigh fading channels.
15 August 2025 in IEEE Open Journal of Vehicular Technology
Verified
Journal Article
Open access
JRJosé Rodríguez-Piñeiro
José Rodríguez-Piñeiro
ZWZhongxiang Wei
Zhongxiang Wei
JWJingjing Wang
Jingjing Wang
CGCarlos A. Gutierrez
Carlos A. Gutierrez
LCLuis M Correia
Luis M Correia
With the developments on Advanced Driver-Assistance Systems (ADAS), autonomous driving and purely unmanned vehicles, such as the Unmanned Aerial Vehicles (UAVs), the pressure on the requirements for Vehicle-to-Everything (V2X) communications has drastically increased during the last few years. However, a new and appealing horizon is open for V2X applications with the advent of the Sixth Generation (6G) of mobile communications. In this paper, we present a review of V2X standards to offer a holistic perspective on the evolution of this technology toward 6G. Then, the key technological enablers for the 6G V2X are identified, namely (a) Non-Terrestrial Networks (NTNs), (b) Ultra Reliable Low Latency Communications (URLLC), (c) Artificial Intelligence (AI), (d) Integrated Sensing And Communications (ISAC) and (e) propagation channel modeling. For each of these technological enablers, the most recent proposals are thoroughly studied and the open challenges and opportunities identified. Our paper intends to serve as a timely roadmap for the development of future 6G V2X networks.
7 July 2021 in IEEE Latin America Transactions
Verified
Journal Article
Closed access
CGCarlos A. Gutierrez
Carlos A. Gutierrez
Oscar CaicedoOscar Caicedo
Oscar Caicedo
Daniel Ulises Campos-DelgadoDaniel Ulises Campos-Delgado
Daniel Ulises Campos-Delgado
The fifth-generation (5G) of mobile communications networks is emerging as a revolutionary technology that will accelerate the development of smart cities and the realization of the information society. This paper aims to provide an introduction to 5G for non-specialists, and a survey of this new technology for those already familiar with mobile communications, covering the conceptualization and the core technologies underpinning 5G networks. The paper also discusses the status of the commercial roll-out of 5G until 2020 from a worldwide perspective and gives a future view of mobile communications beyond 5G.
15 April 2010 in IEEE Transactions on Wireless Communications
Verified
Journal Article
Closed access
CGCarlos A. Gutierrez
Carlos A. Gutierrez
MPMatthias Uwe Pätzold
Matthias Uwe Pätzold
In this letter, we introduce the Riemann sum method (RSM) as an effective tool for the design of sum-of-cisoids (SOC) simulators for narrowband mobile Rayleigh fading channels under non-isotropic scattering conditions. We compare the performance of the RSM with that of the generalized method of equal areas (GMEA) and the Lp-norm method (LPNM), which were until now the only methods available for the design of SOC simulators for non-isotropic scattering channels. The obtained results indicate that the RSM is better suited than the GMEA and the LPNM to emulate the channel's autocorrelation function (ACF), whereas the latter two methods are more precise regarding the approximation of the envelope distribution. The results also show that the benefits of increasing the number of cisoids are more significant in the case of the RSM than in the case of the GMEA and LPNM. Owing to its simplicity and good performance, the RSM can be used to design flexible simulation platforms for the laboratory analysis of mobile communication systems operating in non-isotropic scattering environments.
1 November 2007
Verified
Conference Paper
Closed access
CGCarlos A. Gutierrez
Carlos A. Gutierrez
MPMatthias Uwe Pätzold
Matthias Uwe Pätzold
This paper presents a modified version of the method of equal areas (MEA) for designing simulation models for frequency non-selective mobile fading channels under non- isotropic scattering conditions. The proposed method, called modified MEA (MMEA), is well suited for channel simulators based on a finite sum of complex sinusoids. The combination of the MMEA with the principle of set partitioning is also proposed here as an efficient way to improve the performance of the simulator and to reduce the computational costs. Such a combination results in a new parameter computation method called MMEA with set partitioning (MMEA-SP). The MMEA and the MMEA-SP are quite general and can be applied on any given distribution of the angle of arrival (AOA). However, to exemplify the good performance of both methods, it is assumed that the AOA follows the von Mises distribution. The obtained results demonstrate that the two proposed methods approximate the autocorrelation function (ACF) of non-isotropic scattering channels with high precision.