Design and Analysis of Conformal Antenna for Future Public Safety Communications: Enabling Future Public Safety Communication Infrastructure

Future 4G wireless communication systems include, in their capabilities portfolio, emergency-specific needs, such as data support, broadband communication, and extremely high reliability. An emergency situation can be addressed with undoubtedly more chances of success if augmented information is enabled within the public safety communication novel capabilities. In this article, for a fully augmented information provision based on broadband transmission, a user-end (UE) communication-capabilities enhancement is addressed by deploying multiple antennas without compromising the portability and light weight of first-responder equipment. With this aim, we propose the design of a 4.9-GHz conformal antenna array at the rescuer side (integrated in a helmet) and evaluate its performance in terms of relative data rate gain. The conformal array design is based on traditional patch antennas that consider the need for deployment over an ellipsoidal surface. The antenna array is simulated and then built, and several parameter characterizations (bandwidth, radiation pattern, reflection coefficient, and MC) and measurements are undertaken to ensure the suitability of the design. Furthermore, an analysis of the specific absorption rate (SAR) is performed to guarantee that the exposure to electromagnetic fields is below the standardized levels.The authors would like to thank Prof. Eva Rajo-Iglesias from Universidad Carlos III de Madrid. This work has been partly funded by the Spanish Government through projects CIES (RTC-2015-4213-7), MIMOTEX (TEC2014-61776-EXP) and TERESAADA (TEC2017-90093-C3-2-R) (MINECO/AEI/FEDER, UE

Empirical Rates Characterization of Wearable Multi-Antenna Terminals for First-Responders

Empirical characterization of the achievable rates for a wearable multi-antenna terminal shows the potential advantages of deploying a large number of antennas at the user end. We focus on the challenges and requirements of the broadband communication in future emergency communication systems, specifically addressing the outdoor-to-indoor propagation scenario, where the first responder is within an underground area such as a garage or basement. The measurement campaign undertaken characterizes the flat fading multiple-input multiple-output (MIMO) channel matrices at 3.5 GHz for a maximum of M = 30 antennas deployed at the base station (BS), and N = 12 wearable antennas at the user. The achievable rates are obtained for two transmission strategies that account for the different levels of channel knowledge. In both cases, all the MIMO processing is carried out at the BS.This work was supported in part by the Spanish Government under Project MIMOTEX (TEC2014-61776-EXP), Project CIES (RTC-2015-4213-7), and Project TERESA-ADA (TEC2017-90093-C3-2-R) (MINECO/AEI/FEDER, UE), and in part by the Chilean Government through projects CONICYT under Grant Proyecto Basal FB0821, Grant Fondecyt Iniciación 11171159, and Grant VRIEA-PUCV 039.462/2017.Publicad

Large-scale MIMO textile technology for enhanced terminals

Mención Internacional en el título de doctorThe increasing demand for higher data rates imposed by the next generation of wireless communication networks has postulated Multiple-Input Multiple-Output (MIMO) systems as one of the main technological solutions. While the development of a large number of antennas is relatively feasible at the base station (BS) side due to the available space, it is not so viable at the end user side. Therefore, the user end can be considered as a clear bottle–neck of the communication since in MIMO systems the throughput gains are limited by the minimum number of antennas existing at the transmitter or the receiver. With the aim of overcoming this limitation, in this Thesis textile multi–antenna based terminals are presented. Specifically, the textile solution based on large–scale MIMO technology explored in this work allows to provide the energy and spectral efficiency benefits offered by MIMO technology directly to the end user (e.g. exploiting their own garments or accessories) without compromising the size, weight and, ultimately the portability of the user equipment (UE). Motivated with the aforementioned target, the main results provided by this Thesis can be classified in three. First, the design, fabrication and experimental characterization of different textile antenna arrays is performed. Concretely, one design is developed to be integrated at the backside of a jacket operating at 3.5 GHz, while the other design is developed to be conformed in a helmet operating at 4.9 GHz. Additionally, due to the fact that the textile solution is developed to work in the very close proximity of the human body, offering information regarding the human exposure to electromagnetic fields (EMF) seems to be relevant. Thus, an study to quantify the specific absorption rate (SAR) is also performed. It should be noted that these designs can be applied to emergency scenarios, where first responders can improve their communication capabilities with the deployment of a large number of antennas in their garments. Second, carrying out the experimental characterization of the performance in terms of achievable rates for a textile multi–antenna terminal in order to show the real advantages of deploying a large number of antennas at the user end. With that objective, a measurement campaign that allows to model the wireless channel in relevant Outdoor-to-Indoor (O2I) propagation environments was performed in Valpara´ıso (Chile). Finally, the third part of this Thesis pretends to evaluate the role that textile multi– antenna terminals might play as a part of future public safety network solutions. To this end, a two–hop link network proposal based on advanced long–term evolution (LTE) standard is also proposed. Among other things, the device technology and the network elements required to implement such a network concept, as well as, a possible design principle based on the reliable connectivity principle required by emergency communications, are presented.Programa de Doctorado en Multimedia y Comunicaciones por la Universidad Carlos III de Madrid y la Universidad Rey Juan CarlosPresidente: Juan José Murillo Fuentes.- Secretario: María Julia Fernández-Getino García.- Vocal: Francisco G. Pizarro Torre