Ultra-Wide Band (UWB) was presented as a promising radio technology. Because of their large bandwidth, UWB networks are supposed able to deliver high data rates at short ranges. But after analyzing measurements many works observed saturation of the number of channel Degrees of Freedom (DoF) versus bandwidth. This motivates the work presented in this paper where we focus on sub space behavior to...

......................................................................................................................................... ii

unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Johann Chiang

An overview of the propagation characteristics of ultrawideband (UWB) indoor radio channels is presented with an emphasis on the spatio-temporal channel properties. Extensive measurement results are provided and practical considerations are highlighted. The insight into robust UWB communications and sensor networks, provided by channel modeling, is discussed.