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International audience; This paper presents a new approach to the development of a radio frequency energy harvesting system. Starting from a sensor node to define the constraints of our system such as its energy requirement or its supply voltage, we develop a protocol. It allows us to validate whether it is possible to power such a system with an RF/DC converter. First we study a RF/DC converter capable of converting signals in the ISM band at 2.45 GHz whose ambient power has been previously characterized.

International audience; This paper presents a ranging test conducted in a standard indoor environment using an ultra-wideband (UWB) radar system. The position is determined by jointly estimating the distance using the Energy Detection (ED) method, and the Azimuth angle using Phase Correlation (PC) method. The obtained results show that this UWB ranging system can improve the angular resolution compared to traditional Indoor Localization Systems (ILSs).

National audience; L'objectif de ce travail est le développement d'une dalle pour une interface tactile innovante sur un support souple. La dalle comporte une ligne de transmission imprimée sur un substrat souple et à port d'entrée unique. Le toucher induit une désadaptation locale qui créé une onde réfléchie. L'analyse du coefficient de réflexion en entrée permet de localiser le point de toucher, en utilisant un système d'acquisition basé sur un analyseur de réseaux vectoriel compact. Ce concept de détection est compatible avec des dalles de très grande surface

International audience; A low-complexity time of arrival (TOA) estimation method for Transmitted Reference Ultra-wideband (TR-UWB) signals is proposed. It has a two-step structure adapted to the Time Delayed Sampling and Correlation (TDSC) receiver. The estimation principle is based on the changes of the received signal by means of the derivative of its sliding correlation. The first step of the proposal finds a signal block containing the start of the direct path received pulse (coarse estimate). The second step searches in that block for the actual beginning of the pulse with a higher resolution (fine estimate). The method takes into account the characteristics of the TDSC receiver CMOS prototype which in its actually version can achieve a sampling frequency of 7.5 GHz letting obtain a resolution of around 4 cm. The performance evaluation of the proposed TOA estimation is presented along with some experimental results. This TOA estimator structure is simple, feasible and with a low computing demand, suited for fast mobile localization

The aim of this work is to investigate photonic components and build blocks to enable the delivery of Ultra Wide Band (UWB) radio signal in 60 GHz range, over optical fibre, by using Radio over Fibre (RoF) implementations. These UWB - RoF millimeter waves will be used to manage a Wireless Sensor Network (WSN).

International audience; This paper presents the experimental results of the transmitted reference Ultra-Wideband signals (TR-UWB) detection using a prototype system. The system is based on the 'Time Delayed Sampling and Correlation' (TDSC) detection method and its implementation on a 0.35 CMOS chip with a sampling frequency as high as 7.5 GHz. This platform allows the evaluation of the circuit performance and validates the first synchronization process stage. Detection of such signals has been successfully carried out through an indoor wireless channel, under line of sight (LOS) and non line of sight (NLOS) measurement conditions, both in the sub GHz band (group 1) and low band UWB signals. Simulation of the synchronization process using the received signals was successfully accomplished.

International audience; Detection results of transmitted reference ultra-wideband signals (TR-UWB) are presented. The signals are received through the implementation in CMOS technology of the 'Time Delayed Sampling and Correlation' (TDSC) detection method, which allows the test of its performance and validates the first stage of the synchronization process. This method has been proposed to achieve a UWB system with low cost, low complexity and low power consumption for medium to low data rate applications such as ranging or localization. Detection of such signals has been done successfully in both a direct cable connection as well in a wireless system with a real channel. In both cases they were used in the sub GHz band (group1) and also in the low band UWB signals.

El objetivo de este trabajo es desarrollar una plataforma para transmitir datos en tiempo real en sistemas basados en redes de sensores. Para validar el nuevo concepto de detección de pulsos propuesto por el Laboratorio de Electrónica y Física (EPH) de la universidad Télécom SudParis (Evry, Francia), se diseñó y se realizó un circuito receptor VLSI (Very Large Scale Integration) en el laboratorio empleando la tecnología CMOS 0.35 μm. Este nuevo método de detección es llamado TDSC (Time Delayed Sampling & Correlation). Las prestaciones del chip TDSC empleado ya fueron comprobadas en proyectos anteriores mediante un sencillo emisor y un receptor realizados en tarjetas impresas de test. La finalidad de este proyecto final de carrera es continuar con la validación de este concepto mediante la transmisión de datos en un formato predefinido y, sobre todo, incorporar las operaciones de correlación y sincronización de datos entre el emisor y el receptor. Este es un punto importante para todo sistema de comunicaciones, pero especialmente en este caso porque tenemos que sincronizar la señal en una anchura de unos pocos nanosegundos. El trabajo realizado ha sido: proposición y diseño de nuevas tarjetas de de test emisoras y receptoras para hacer funcionar el sistema compuesto por un emisor y el receptor TDSC, implementación en un microcontrolador del proceso de transmisión de pulsos UWB (Ultra Wide Band), estudio del estado del arte de las comunicaciones LDR-UWB (Low Data Rate-Ultra Wide Band), especialmente de los diferentes tipos de receptores y las ventajas de cada uno y, finalmente, un estudio de la compatibilidad con la norma IEEE 802.15.4a de los protocolos utilizados en el emisor y en el receptor, sobre todo en las capas física (PHY) y de control de acceso al medio (MAC).

International audience; While GPS high quality products supplied by leading global components (Motorola, Analog Devices, Sirf, Maxim, Qualcomm ...) are available, many research works are carried out in order to improve sensitivity, response time, dynamics, accuracy, size and power consumption. In addition, continuity of the positioning service between outdoor and indoor appears as a must for the next years. Most of the receivers are limited to a single standard and do not offer positioning services in areas where satellites are not available. Although many techniques have been proposed these last ten years, ranging from High-Sensitivity GNSS (Global Navigation Satellite System) to sensor networks, through Assisted-GNSS or WLAN based approaches, no ultimate solution seems yet to provide the answer to the indoor positioning problem, probably crucial to Location Based Services. In order to enhance receiver performance in harsh environments where significant multipath problems are present and ensure continuity of the positioning service between outdoor and indoor, digital receiver processing (Acquisition and tracking) could benefit from the use of different RF bands in GNSS systems. Hence, implementing multiband GNSS receiver in mobile equipment can be considered as a promising solution in the navigation domain. We propose then to design a multistandard GNSS receiver including the GPS L1, L2 and L5 bands [1], the GLONASS G1 band [2] and also the Galileo E1 and E5 bands [3]. To the authors knowledge, only one chip, the MAX2769 [4], addresses this three systems but does not include a digital stage for data signal processing. Proposed architecture, in this work, is based on an RF subsampling down-conversion topology [5]. A fixed subsampling frequency is chosen to properly down-convert the three constellations RF bands to a fixed IF band, which relaxes the IF filter design. A Direct Digital Converter is designed to perform quadrature down-conversion to baseband. The front-end design takes into account the main requirements implied by the indoor positioning methods [6]. Hence, the proposed architecture can implement in the digital stage GNSS approaches for indoor positioning, as described in previous papers [7], and [ 8] for the associated multipath problem in indoor environments. The design methodology of this innovative GPS/GLONASS/GALILEO receiver architecture providing outdoor to indoor positioning service is fully described by authors in previous work [9]. In the present paper, we propose to study the GNSS RF-Front-End prototype based on commercial components and validate the total gain and noise factor of the chain by RF simulation, and the BER by RF/DSP co-simulation

International audience; Recently a new detection method for TR-UWB systems called Time Delayed Sampling and Correlation (TDSC) has been proposed. This new method overcomes the major diffi-culties in a traditional TR-UWB detection method based on a wide band delay line. TDSC is based on a time to space conversion realizable by an analog waveform sampler. In this paper a first prototype is presented designed using low cost CMOS 0.35µm technology. Details, simulated results, and layout of the first prototype are presented in the paper

International audience; The major challenges in the timing acquisition for transmit-ted reference ultra-wideband (TR-UWB) communication systems are enormous search space, multiple user interfer-ence (MUI) environments and accurate delay implementation. In this paper we propose a very fast synchronisation method and a simple multiuser scheme that will be used with a low cost digitally delayed TR system called Time Delayed Sampling and Correlation (TDSC)