Matthew L. Welborn

The importance of fractional bandwidth in ultra-wideband pulse design

Ultra-wideband (UWB) communications systems provide extremely high data rates while using low transmit power relative to narrowband systems. Previous research concludes that such systems have characteristics that make them appropriate for high-speed wireless network applications. One of the distinguishing aspects of the UWB signal is an extremely high fractional bandwidth when compared with conventional narrowband systems. This paper describes how a large fractional bandwidth leads to lower worst-case fading in the presence of multipath for UWB communications systems, thereby providing a significant advantage for a low-power wireless systems. Also included are measurements made using an actual UWB communications systems showing the magnitude of signal strength variations due to multipath interference.