Ultra-wideband communications : An overview

This paper presents an overview of ultra-wideband (UWB) communications systems, i.e., systems with very large relative and/or absolute bandwidth. The large bandwidth and low power spectral density mandated for UWB systems allows their use as overlays over existing (legacy) systems, i.e., they can be used in the same frequency range as existing systems without causing undue interference. We also describe the most common types of UWB systems, including time-hopping impulse radio, frequency hopping, and multi-band OFDM. We furthermore discuss interference aspects and the peculiarities of UWB propagation channels.