Applicability Limits of Simplified Human Blockage Models at 5G mm-Wave Frequencies

This paper analyzes the feasibility of using a simple diffraction model to compute the blocking of the human body to millimeter wave radio frequencies in indoor environments. The model makes a set of approximations that are evaluated to determine the applicability limits of such simplified approach, in particular for the human body blockage case. The work presented here: (1) describes briefly the mathematical support that is used to model the concealment using the Knife-Edge model, (2) identifies the potential simplifications applicable to the mathematical model implementation that allow a 3D geometric human body to be modelled with simple 2D shapes, (3) characterizes the polarization influence on the mm-wave blocking for such simplified human body models.This work was supported by the H2020 Marie Curie program, with project grant no: 766231 WAVECOMBEITN-2017Romero-Peña, JS.; Cardona Marcet, N. (2019). Applicability Limits of Simplified Human Blockage Models at 5G mm-Wave Frequencies. IEEE. 1-5. http://hdl.handle.net/10251/1319941

Key Enabling Technologies for 5G: Millimeter-Wave and Massive MIMO

[EN] 5G wireless networks are expected to operate with orders of magnitude higher performance than the current 4G deployments. The demand for 5000 times higher data rates leads to the necessity of finding new techniques to increase spectral efficiency and of exploring new frequency bands above 6 GHz. It has been proved that from UHF up to C band, a significant increase in system spectral efficiency can be reached through various techniques, such as Coordinated Multi-Point (CoMP), Massive Multiple-Input-Multiple-Output (MIMO), and interference management and cancellation; still, the resulting performance will not cope with the full expectations of IMT-2020 and 5G-PPP requirements for 5G networks, mainly in terms of offering 10 Gbps peak data rates with connection densities of 100 k¿1 M devices/km2. To overcome this limitation, the future architecture of such 5G networks is being defined to be deployed on small cells and to use higher frequency bands, such as super high frequency (SHF, 3¿30 GHz) or extremely high frequency (EHF, 30¿300 GHz), also referred as to centimeter and millimeter wave bands, respectively.Cardona Marcet, N.; Correia, LM.; Calabuig Soler, D. (2017). Key Enabling Technologies for 5G: Millimeter-Wave and Massive MIMO. International Journal of Wireless Information Networks. 24(3):201-203. doi:10.1007/s10776-017-0366-zS20120324

Initial Delay Domain UWB Channel Characterization for In-body Area Networks

Wireless Body Area Networks (WBANs) have increased the attention of the research community for the next generation wireless medical devices. Among others, Wireless Capsule Endoscopy (WCE) aims to transmit better quality images. For this, the Ultra Wideband (UWB) frequency band is becoming a good alternative to currently allocated frequencies for in-body networks, allowing higher data rate and having a low power transmission. Common channel characterization in WBANs are performed in frequency domain, i.e., analyzing the received power as a function of frequency. Nevertheless, indepth studies in delay domain analyzing the impulse response of the channel are barely considered in current literature. In this paper, an initial study in delay domain, i.e., the Power Delay Profile (PDP) characteristics, is performed. Moreover, a comparison between the channel response in frequency and delay domain is performed. This work gives an insightful view of the impulse response of the channel for in-body to on-body communications. For that, an extensive campaign of phantom measurements and software simulations are conducted.This work was supported by the European Union’s H2020:MSCA:ITN program for the ”Wireless In-body Environment Communication- WiBEC” project under the grant agreement no. 675353. This work was also funded by by the European Union’s H2020: MSCA: ITN program for the ”mmWave Communications in the Built Environments - WaveComBE” project under the grant agreement no. 766231.Pérez-Simbor, S.; Garcia-Pardo, C.; Cardona Marcet, N. (2019). Initial Delay Domain UWB Channel Characterization for In-body Area Networks. IEEE. 1-5. https://doi.org/10.1109/ISMICT.2019.8743767S1

Propuesta de conectividad a Internet para zonas rurales mediante un canal de retorno para ISDB-Tb

Se propone la definición de una nueva tecnología de Televisión Digital Terrestre (TDT) basada en los estándares DVB-RCT y DVB-T2, denominada DVB-RCT2 (Digital Video Broadcasting- Return Channel Terrestrial 2nd Genearation), que permitirá disponer de un canal de retorno para el estándar ISDB-Tb (Integrated Services Digital Broadcasting ¿ Terrestrial Brasil). El objetivo de esta nueva tecnología es brindar y/o mejorar el acceso a Internet en zonas rurales de los países de América Latina, utilizando la infraestructura de TDT existente, mediante lo cual se podría aumentar la penetración a Internet en este tipo de zonas, disminuyendo los costos de implementación.Radicelli-García, CD.; Cardona Marcet, N. (2015). Propuesta de conectividad a Internet para zonas rurales mediante un canal de retorno para ISDB-Tb. Cultura Cientifica y Tecnologica. 12(55):4-15. http://hdl.handle.net/10251/78993S415125

Irregular MultiFocal Reflector for Efficient mmWave Propagation in Indoor Enviroments

[EN] In future implementations of 5G systems , it isessential the use of the spectrum in the range of mm-Wavesfrequencies , in order to offer to the users the bandwidthproposed in the standard. However , using this frequency rangelead to many technical difficulties in which the most importantchallenge is the critical attenuation of the signal in non-line-of-sight (NLOS) environments in indoor environments. Therefore isessential to plan strategies that allow us to mitigate the problemof signal attenuation in this kind of complex environments andensure the viability of using this technology in short term. Thenthe objective of this research is the design of a passive reflectorthat allow us to redirect the energy of the transmitting antennaefficiently in order to avoid the obstacles of the environment ,and therefore avoid excessive losses .This work was supported by the H2020 Marie Curie program, with project grant no: 766231 WAVECOMBE-ITN2017Romero-Peña, JS.; Cardona Marcet, N. (2020). Irregular MultiFocal Reflector for Efficient mmWave Propagation in Indoor Enviroments. IEEE. https://doi.org/10.23919/EuCAP48036.2020.9136074

Parámetros configurables de capa física y MAC de un nuevo estándar de TDT con canal de retorno inalámbrico para proporcionar conectividad a Internet en zonas rurales de Latinoamérica

[ES] Este artículo propone una guía para la configuración de los parámetros de capa física y MAC de un nuevo estándar de televisión digital terrestre (TDT) de segunda generación con canal de retorno inalámbrico de nominado DVB-RCT2, particularizando en la capa física; (i) los modos de transmisión, (ii) las estructura s de ráfagas (BS1, BS2, BS3), y (iii) los esquemas de acceso al medio (MAS) para diferentes tamaños de FFT; y en la capa MAC (i) los modos de acceso, considerando un ancho de banda de 6 MHz. Para obtener los datos de esta investigación se ha emulado las condiciones del canal RCT2 en un laboratorio de radiodifusión, donde se ha generado el flujo de transporte de RCT2, obteniendo valores sobre el funcionamiento tanto de capa física como de MAC, que están representados en tablas, constatando así las capacidades de DVB-RCT2 sobre DVB-RCT, lo que lo convierte en una interesante alternativa para proporcionar acceso a Internet a zonas rurales.[EN] This paper proposes the elaboration of a guide to configure the parameters of a physical and MAC layer of a new second-generation digital terrestrial television (TDT) with a wireless return channel called DVB-RCT2, particularly on the physical layer; (i) transmission modes, (ii) the burst structures (BS1, BS2, BS3), and (iii) the medium access schemes (MAS) for different FFT sizes; and as for the MAC layer (i) the access modes by considering an internet band of 6 MHz. To obtain the information, the conditions of the RCT2 channel have been emulated in a broadcasting laboratory, where the transport stream (TS) has been generated to get different values on the operation from both the physical layer and MAC which are represented in different charts that demonstrate the DVB-RCT2 capacity over its predecessor DVB-RCT which makes this proposal an interesting alternative to provide internet access to rural areas.Radicelli García, CD.; Cardona Marcet, N. (2016). Parámetros configurables de capa física y MAC de un nuevo estándar de TDT con canal de retorno inalámbrico para proporcionar conectividad a Internet en zonas rurales de Latinoamérica. DYNA. 83(198):16-26. doi:10.15446/dyna.v83n197.52242S16268319

Configurable node density generation with application to hotspot modelling

Mobility models are very relevant mainly when studying the performance of wireless systems by means of computer simulations. The main problem arises when deciding the best mobility model for a particular application. In some cases, it is very important to emulate hotspots or, in general, zones with different user (or node) densities. Current models do not allow complete control over hotspots, or in other words, they do not allow any general node density to be defined in the simulation area. Usually, when hotspots are modelled, closed zones are created with different numbers of users in each area, thus ensuring a fixed node density in each area. However, this approach results in an unfair comparison among users since they cannot move across zones. This paper proposes a new mechanism to solve these drawbacks. Using this mechanism, any general node density can be emulated allowing nodes to move around the entire simulation area. Any mobility model can be applied together with this density control mechanism, provided that the mobility model ensures a uniform node distribution. © 2010 Elsevier Ltd.This work has been funded by the Spanish Ministry of Science and Innovation under project TEC2008-06817-C02-01/TEC.Calabuig Soler, D.; Monserrat Del Río, JF.; Cardona Marcet, N. (2011). Configurable node density generation with application to hotspot modelling. Mathematical and Computer Modelling. 53(11-12):2229-2237. https://doi.org/10.1016/j.mcm.2010.08.028S222922375311-1

Analysis of the Localization Error for Capsule Endoscopy Applications at UWB Frequencies

Localization for Wireless Capsule Endoscopy (WCE) in the Ultra-Wideband frequency band is a very active field of investigation due to its potential advantages in future endoscopy applications. Received Signal Strength (RSS) based localization is commonly preferred due to its simplicity. Previous studies on Ultra-Wideband (UWB) RSS-based localization showed that the localization accuracy depends on the average ranging error related to the selected combination of receivers, which not always is the one experiencing the highest level of received power. In this paper the tendency of the localization error is further investigated through supplementary software simulations and previously conducted laboratory measurements. Two-dimensional (2D) and three-dimensional (3D) positioning are performed and the trend of the localization error compared in both cases. Results shows that the distribution of the selected path loss values, corresponding to the receivers used for localization, around the in-body position to estimate also affects the localization accuracy.This work was supported by the H2020:MSCA:ITN program for the “Wireless In-body Environment Communication- WiBEC” project under the grant agreement no. 675353. This work was also supported by the European Union’s H2020:MSCA:ITN program for the ”mmWave Communications in the Built Environments - WaveComBE” project under the grant agreement no. 766231.Barbi, M.; Pérez-Simbor, S.; Garcia-Pardo, C.; Cardona Marcet, N. (2019). Analysis of the Localization Error for Capsule Endoscopy Applications at UWB Frequencies. IEEE. https://doi.org/10.1109/ISMICT.2019.8743813

Fairness-Driven Fast Resource Allocation for Interference-Free Heterogeneous Networks

Resource allocation in heterogeneous wireless networks is a complex problem. This letter addresses this problem maximizing the sum of logarithms of received rates. From this function, and using the Karush-Kuhn-Tucker (KKT) conditions, this paper proposes an iterative algorithm for allocating resources, which is much faster than conventional techniques. This fast response can be used to optimize larger regions, getting closer to the performance of global and centralized algorithms. © 2012 IEEE.This work was supported by a Marie Curie International Outgoing Fellowship of the European Commission under the project COMIC.Calabuig Soler, D.; Monserrat Del Río, JF.; Cardona Marcet, N. (2012). Fairness-Driven Fast Resource Allocation for Interference-Free Heterogeneous Networks. IEEE Communications Letters. 16(7):1092-1095. doi:10.1109/LCOMM.2012.051512.120720S1092109516

Time Diversity in Mobile DVB-T2 Systems

DVB-T2 implements a very flexible time interleaving that allows multiple tradeoffs in terms of time diversity, latency and power saving. In this paper, we study in detail these tradeoffs in the context of mobile reception. Together with time diversity, we also investigate the impact of reduced time de-interleaving memory and Alamouti-based MISO in the mobile reception of DVB-T2 services. In addition, we propose the utilization of upper layer FEC protection in order to overcome the limitations of the DVB-T2 physical layer for the provision of long time interleaving, and enable fast zapping. The performance is evaluated by means of simulations in mobile channels that include the presence of fast fading and shadowing in the received signal. © 2010 IEEE.Manuscript received October 13, 2010; revised April 22, 2011; accepted May 11, 2011. Date of publication July 25, 2011; date of current version August 24, 2011. This work was supported in part by the Spanish Ministry of Industry, Tourism, and Commerce under the Celtic project Enabling Next-Generation Networks for Broadcast Services ENGINES (TSI-020400-2010-108). The work of D. Gozalvez was supported by the FPU Grant AP2008-03293 of the Spanish Ministry of Education.Gozálvez Serrano, D.; Gómez Barquero, D.; Vargas, D.; Cardona Marcet, N. (2011). Time Diversity in Mobile DVB-T2 Systems. IEEE Transactions on Broadcasting. 57(3):617-628. doi:10.1109/TBC.2011.2161189S61762857