Experimental analysis of UWB signal performance in a constrained environment for railway application

International audienceIn the railway application, in order to establish the communication between wagons, some technologies are proposed such as the ZigBee and HTN (Hybrid Networking Technology). However, these techniques have some limitations such as: the low data rate, non-secured transmission and interferences. The Ultra Wide Band (UWB) technology presents a good alternative and a good candidate for this application. In recent years, UWB communication systems have received significant attention from both the industry and the academia. In February 2002, the Federal Communications Commission (FCC) allocated 7500 MHz of spectrum (from 3.1 GHz to 10.6 GHz) for use by UWB devices. This ruling has helped to create new standardization efforts, like IEEE 802.15.3a, which focus on developing high speed wireless communication systems. The application of the UWB radio technique in the transport is a more recent topic that is thoroughly researched considering several factors including the nature of the transport propagation environment; the use of adequate transmitting/receiving duty cycle (LDC); the number of devices using UWB technology, the types and levels of interferences. Regulation bodies have considered these railway applications. Impulse Radio Ultra Wideband (IR-UWB) systems have been studied for their inherent advantages of coexistence with narrowband systems with high data rate over short distances with sufficiently small amount of transmitted power. The UWB systems are highly susceptible to interference between the coexisting narrowband systems because of very low transmission power. This paper considers the use of the UWB radio technology for railway application. In this paper, we evaluate the communication performance in constrained environment for the railway application

Qualitative behavior of halo nuclei elastic scattering angular distributions

We propose a novel decomposition of the scattering amplitude appropriate for a qualitative understanding of angular distributions in elastic collisions of neutron-rich nuclei. This decomposition allows one to isolate the contributions of the nuclear attraction to the elastic scattering amplitude. © 1993 The American Physical Society.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Quantal particle flux and nuclear halo effects

We propose a method to study refractive scattering by looking at the quantal particle flux within the volume occupied by the nuclear potential. The method is applied to discuss the nuclear halo effects in the elastic scattering of Li11 and C11 on C12 at E/A∼60 MeV. © 1995 The American Physical Society.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

V2X Communications Applied to Safety at Level Crossings

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