Alexis Bisiaux

An ultra-wide band umbilical cord for cognitive radio systems

This paper describes how cognitive radio (CR) could benefit from software-defined radio (SDR) compatible ultra-wide band (UWB) systems. It introduces the notion of umbilical cord that can keep a CR device connected to its surrounding world, thanks to sensing and low speed over-the-air reconfiguration (OTAR) means provided by low-data rate (LDR) systems, and to fast OTAR downloading facilities based on high-data rate (HDR) hot spots. A particular UWB architecture supporting SDR-compatible technological constraints is proposed as candidate to realize this promising combination of capabilities

Microwave (De) Multiplexer for Ultra-Wideband (UWB) Non-Coherent High Data Rates Transceiver

The following topics are dealt with: low-loss planar multiplexer/demultiplexers; ultra-wideband high data rate (UWB HDR) transceivers; impulse radio; microstrip passive quadriplexers; 2nd order filters and open-loop resonators

A multi-band IR-UWB HDR transceiver: architecture and indoor channel measurements

This paper presents an architecture of an IR-UWB MB-OOK non-coherent transceiver realized at Mitsubishi Electric. Channel measurements in real indoor environment based on this realized prototype are provided. The different components of this transceiver are described. A comparison between the use of directional and omnidirectional antennas at both emission and reception is presented. Then, a data rate estimation of the communicating system is given. Measurements are performed for both LOS and NLOS short-range indoor communications.

Vers les 20 kbit/s en transmission décamétrique ionosphérique : une application du traitement d'antenne sur des capteurs colocalisés

RésuméCet article décrit un système opérationnel de transmission numérique en gamme décamétrique (H.F.) visant à augmenter le débit binaire de façon significative par rapport à la norme actuelle (4800 bit/s). Pour cela, un traitement d’antenne est mis en œuvre sur un ensemble de capteurs colocalisés présentant une diversité de leurs réponses spatiales. La dépendance de la polarisation reçue vis-à-vis de la direction d’arrivée est exploitée pour assurer une décorrélation efficace des signaux reçus en absence de tout déphasage géométrique. Les techniques de traitement du signal en réception s’appliquent sur la sortie du filtre spatial; elles font appel, tant pour la synchronisation que pour le filtrage (algorithme lms) à des solutions classiques et éprouvées utilisant des séquences d’apprentissage. Une liaison expérimentale de portée égale à 250 km a été établie afin de tester l’influence du choix de la forme d’onde sur les performances en réception. Les résultats obtenus sont conformes à l’objectif fixé puisque le débit binaire atteint 20 kbit/s dans une bande de 6 kHz.AbstractThis paper presents an operational system of digital transmission within the h.f. frequency range, aiming at a significant increase of the data transfer rate compared with the current standard (4800 bit/s). Therefore, an array processing algorithm performs with a set of collocated sensors, the spatial responses of which are different one from each other. The dependence of the incoming polarization relatively to the direction of arrival induces a significant decorrelation of the received signals though no geometrical phase exists. Signal processing techniques run at the output of the spatial filter resorting for the synchronisation and the filtering (lms algorithm) to classical and well-tested techniques involving training sequences. An experimental radio link with a 250 km range has been set up to test the sensibility of the performances in reception regarding the choice of waveforms. The operational results reach the expected goal as the data transfer rate increases up to 20 kbit/s in a bandwidth of 6 kHz.