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Belhabib M.,CEA Grenoble | D'Errico R.,CEA Grenoble | Uguen B.,IETR
2016 10th European Conference on Antennas and Propagation, EuCAP 2016 | Year: 2016

This paper presents a comparison of different three dimensional (3D) MIMO Over-The-Air (OTA) multi-probe configurations. Spatial correlation is used as metric to evaluate the setup accuracy, considering different antenna probes emplacements and Elevation Spread (ES). Simulation results are presented in uniform and single cluster channel models for spherical and cylindrical 3D OTA. © 2016 European Association of Antennas and Propagation.

Belhabib M.,CEA Grenoble | D'Errico R.,CEA Grenoble | Bernard U.,IETR
2016 10th European Conference on Antennas and Propagation, EuCAP 2016 | Year: 2016

This paper investigates the effect of the radius of a Over-The-Air (OTA) multi-probes ring employing half-wavelength dipoles, on the emulated spatial correlation. The Device Under Test (DUT) is considered randomly oriented in the test zone. Based on the correlation error metric, antenna effect on correlation is evaluated for a Clarke's and single cluster scenarios and OTA two-dimensional rings with up to 32 probes. © 2016 European Association of Antennas and Propagation.

Cheaito A.,INSA Rennes | Saad Farah M.,INSA Rennes | Crussiere M.,INSA Rennes | Helard J.-F.,INSA Rennes | Louet Y.,IETR
IEEE Wireless Communications and Networking Conference, WCNC | Year: 2017

The aim of this paper is to analytically evaluate the spectral regrowth at the output of a transmitter due to the nonlinear components such as the power amplifier (PA). Therefore, we propose a generalization of existing closed-form expression for the Power Spectral Density (PSD) of nonlinear amplified multicarrier signals to be valid for any type of modulation. Then, we derive the PSD of the amplified multicarrier signal taking into account the predistortion technique. To the best of our knowledge, no analytical PSD expression of the transmitted signal taking into account the predistortion technique exists in the literature. Such analytical expression could be of particular interest to those involved in the design of cellular communications systems. In fact, this analytical expression is very useful to determine the optimal configuration of the PA and the predistortion technique that allows to obtain the maximum PA efficiency while satisfying the linearity requirements. © 2017 IEEE.

Formont P.,ONERA | Formont P.,Supelec | Pascal F.,Supelec | Vasile G.,CNRS GIPSA Laboratory | And 3 more authors.
IEEE Journal on Selected Topics in Signal Processing | Year: 2011

This paper presents a general approach for high- resolution polarimetric SAR data classification in heterogeneous clutter, based on a statistical test of equality of covariance matrices. The Spherically Invariant Random Vector (SIRV) model is used to describe the clutter. Several distance measures, including classical ones used in standard classification methods, can be derived from the general test. The new approach provide a threshold over which pixels are rejected from the image, meaning they are not sufficiently close from any existing class. A distance measure using this general approach is derived and tested on a high-resolution polarimetric data set acquired by the ONERA RAMSES system. It is compared to the results of the classical α decomposition and Wishart classifier under Gaussian and SIRV assumption. Results show that the new approach rejects all pixels from heterogeneous parts of the scene and classifies its Gaussian parts. © 2010 IEEE.

Praho B.,Orange Group | Tlich M.,INNOVAS | Moulin F.,Orange Group | Zeddam A.,Orange Group | Nouvel F.,IETR
2011 IEEE International Symposium on Power Line Communications and Its Applications, ISPLC 2011 | Year: 2011

The indoor PLC (Power Line Communications) and VDSL2 (Very high bit-rate Digital Subscriber Line) technologies share the same frequency band up to 30 MHz. Behind the VDSL2 access network, the power line network is envisaged to be used like an home network in order to transit TV flows from the VDSL2 modem to the set-top-box. In many customer premises, power line cables are nearby telephone cables and consequently unwanted couplings could occur generating hence VDSL2 QoS decrease. This paper describes an experimental study of PLC coupling effect on VDSL2. Two approaches are followed in order to highlight this coupling effect. The first one consists in studying the PLC coupling effect on VDSL2 relying in different coexistence scenarios made in laboratory. The second one is based on field test measurements into several houses: coupling noises are measured on phone plugs when PLC signals are transmitted in sockets. © 2011 IEEE.

Wipliez M.,IETR | Raulet M.,IETR
International Journal of Embedded and Real-Time Communication Systems | Year: 2012

Dataflow programming has been used to describe signal processing applications for many years, traditionally with cyclo-static dataflow (CSDF) or synchronous dataflow (SDF) models that restrict expressive power in favor of compile-time analysis and predictability. More recently, dynamic dataflow is being used for the description of multimedia video standards as promoted by the RVC standard (ISO/IEC 23001:4). Dynamic dataflow is not restricted with respect to expressive power, but it does require runtime scheduling in the general case, which may be costly to perform on software. The authors presented in a previous paper a method to automatically classify actors of a dynamic dataflow program within more restrictive dataflow models when possible, along with a method to transform the actors classified as static to improve execution speed by reducing the number of FIFO accesses (Wipliez & Raulet, 2010). This paper presents an extension of the classification method using satisfiability solving, and details the precise semantics used for the abstract interpretation of actors. The extended classification is able to classify more actors than what could previously be achieved. Copyright © 2011, IGI Global.

Miry C.,IETR | Gillard R.,IETR | Loison R.,IETR
IET Microwaves, Antennas and Propagation | Year: 2010

This study presents an extension of the recently published dual-grid finite-difference time-domain (FDTD) method, which aims at simulating efficiently body area network problems. It consists in splitting the overall simulation into several classical FDTD simulations sequentially executed with an appropriate mesh. It is proposed as an accurate and fast way of modelling integrated antennas and especially analysing the transmission between a body implanted antenna and a receiving antenna located in the nearby environment. © 2010 The Institution of Engineering and Technology.

Zhang P.,IETR | Jacques E.,IETR | Rogel R.,IETR | Bonnaud O.,IETR
Solid-State Electronics | Year: 2013

P-type and N-type multi-gate vertical thin film transistors (vertical TFTs) have been fabricated, adopting the low-temperature (T ≤ 600 C) polycrystalline silicon (polysilicon) technology. Stacked heavily-doped polysilicon source and drain are electrically isolated by an insulating barrier. Multi-teeth configuration is defined by reactive ion etching leading to sidewalls formation on which undoped polysilicon active layer is deposited. All the polysilicon layers are deposited from low pressure chemical vapor deposition (LPCVD) technique. Vertical TFTs are designed with multi gates, in order to have a higher equivalent channel width. Different active layer thicknesses have been attempted, and an ION/IOFF ratio slightly higher than 105 is obtained. P-type and N-type vertical TFTs have shown symmetric electrical characteristics. Different geometrical parameters have been chosen. IOFF is proportional to the single channel width, and to the tooth number. ION is only proportional to the tooth number. These devices open the way of a CMOS-like technology. © 2013 Elsevier Ltd. All rights reserved.

Bellez S.,IETR | Bourlier C.,IETR | Kubicke G.,Directorate General of Armaments
IEEE Transactions on Antennas and Propagation | Year: 2015

An efficient hybrid KA-EFIE formulation is deployed to analyze the electromagnetic (EM) scattering from a 3-D perfectly electric conducting (PEC) object buried beneath a 2-D dielectric rough surface. In this approach, the electric and magnetic current densities on the rough surface are analytically obtained through the current-based Kirchhoff approximation (KA), whereas the electric current density on the buried object is rigorously determined by solving the electric field integral equation (EFIE) using the Galerkin's method of moments (MoM) with Rao-Wilton-Glisson (RWG) basis functions. The KA-EFIE matrix system is then efficiently solved by the iterative propagation-inside-layer-expansion (PILE) method combined with the algebraic adaptive cross approximation (ACA). The current densities on the dielectric rough surface are thereafter used to handle the bistatic normalized radar cross-section (NRCS) patterns. The proposed hybrid approach allows a significant reduction in computation time and memory requirements compared to the rigorous Poggio-Miller-Chang-Harrington-Wu (PMCHW)-EFIE formulation which requires solving a large MoM matrix equation. Moreover, the hybridization of the ACA algorithm with the PILE method improves further the computational cost thanks to the rank-deficient propriety of the coupling matrices. To validate the hybrid approach, we compare its results with those of the rigorous PMCHW-EFIE approach. © 2015 IEEE.

Haessig P.,IETR | Ben Ahmed H.,SATIE Laboratory | Multon B.,SATIE Laboratory
2015 IEEE Eindhoven PowerTech, PowerTech 2015 | Year: 2015

Energy Storage Systems (ESS) are often proposed to mitigate the fluctuations of renewable power sources like wind turbines. In such a context, the main objective for the ESS control (its energy management) is to maximize the performance of the mitigation scheme. © 2015 IEEE.

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