Video (in French, Jérôme Vernez)
Research and prototype of mobile ad-hoc senders and receivers that radiate very little power (order of μWatts), using Ultra-Wide Band (UWB) transmission technology. Rationales for the proposed project and state of the art UWB Communication. UWB is characterized by an extremely broad use of the radio spectrum which makes it relatively robust against channel impairments such as multipath fading. The primary characteristic of Ultra Wide Band (UWB) communication is that the power spectral density of the envisaged signaling strategy is extremely wideband (on the order of GHz in the 3.1-10.6 GHz band) and very low (on the order of thermal noise for a receiver beyond a distance of 5 meters from its correspondent transmitter).
The latter is due to the strong limitation on the average emission level (-41 dBm/MHz) to limit the interference with the multitude of systems using regulated and unregulated spectrum in common with future UWB systems. The most common UWB transmission waveform is based on transmitting information through the use of short-term impulses, whose positions are modulated by a binary information source. This if often referred to as impulse radio. Impulse radio is a promising candidate for military imaging systems as well as other non-commercial sensor network applications because of its robustness to interference from signals (potentially from other non-UWB systems) occupying the same bandwidth. Impulse implementation simplicity and low-power consumption are also often cited as characteristics of impulse radio, although these have yet to be demonstrated in practical systems. Standards proposals for indoor Wireless Personal area Networks (WPAN) in the 3-5 GHz band (802.15.3) and for short-range sensors (802.15.4) are also considering this type of transmission scheme as an alternative to more classical signaling waveforms. In addition to Impulse Radio, FM UWB appears as an alternative that avoids pulse synchronization and low duty cycles while exhibiting low spectral roll-off and low power consumption. It may play a complementary role in low-power, low data rate (LDR) applications.
- James Colli-Vignarelli , Jérôme Vernez, Ruben Merz , Catherine Dehollain, Stephan Robert, Jean-Yves Le Boudec, « Concurrent Transmissions in IR-UWB Networks : an Experimental Validation », ICUWB’09.