Intelligent transports systems based on UWB technologies
Résumé
Ultra Wide Band (UWB) may offer very efficient solutions for various communication and localisation transport applications. We propose to use this technique to establish communication vehicle- to- vehicle and vehicle- to-infrastructure. In fact, compared to traditional carrier-based, Ultra-Wide Band (UWB), or carrier-less, systems implement new paradigms in terms of signal generation and reception. Thus, designing an UWB communication and localisation system requires understanding of how excess bandwidth and very low transmitted powers can be used jointly to provide a reliable radio link. UWB offers system transceiver potential for very simple implementations. Two approaches have emerged, which meet all the communication requirements: impulse and multi-band systems. The first system operates between 3.1 to 10.6 GHz in a single frequency band. The second one exploits the division of the bandwidth into sub-bands (each sub-band width being up to around 500 MHz wide). The present work is concerned in the second approach. So, we propose to use orthogonal functions called Modified Gegenbauer Functions (MGF) in UWB systems. Different scenarios are studied and compared in the scope of a system offering communication and location capabilities for subway trains. To evaluate the performance of the proposed communication system, the Bit Error Rate (BER) values are calculated and analyzed in the presence of multi-user interference, assuming asynchonous users. The performance of localisation system is evaluated in terms of localisation error. This study shows that Gegenbauer functions offer the performance required for our multi-band UWB communication and location transport systems.