Ultrawideband through-the-wall propagation

Abstract

The propagation of ultrawideband (UWB) signals in indoor environments is an important issue with significant impacts on the future direction and scope of UWB technology. The propagation of UWB signals is governed, among other things, by the properties of materials in the propagation medium. The information on electromagnetic properties of construction materials in the UWB frequency range would provide valuable insights into the appreciation of the capabilities and limitations of UWB technology. Although electromagnetic properties of certain construction materials over relatively narrow bandwidths in GHz frequency ranges are available, ultrawideband characterisation of most typical construction materials for UWB communication purposes has not been reported. In narrowband wireless communications, only the magnitude of insertion loss has been the quantity of interest. But for UWB signals, in addition to the magnitude, the phase information is an equally important factor that needs to be accounted for. In fact, UWB signals not only suffer attenuation when propagating through walls, but also suffer distortion due to the dispersive properties of the walls. This research examines propagation through typical construction materials and their ultrawideband characterisation. Ten commonly used construction materials are chosen for this investigation. Results for the dielectric constant and loss tangent of the materials over the UWB frequency range are presented. Accuracy of the measured results is discussed and distortions of UWB signals due to the dispersive properties of wall materials are addressed.

Simulation of UWB distortion combined with indoor spatio- temporal channels

“…According to the characteristics of clusters, Class-III clusters are dominated by the direct signals, single reflection and multi-reflection between LOS connections. Therefore, its signal strength, indicated by a solid line, is higher than pulse signals Referring to dielectric constants of furniture materials in propagation paths [9][10], properties of dielectric constants with frequency variation are also taken into account, thus simulation at each subband examines pulse distortions from different dielectric constants. The effects of frequencydependent dielectric constants of materials for individual UWB propagation paths are characterized with results in Fig.…”

An approach to ultra-wideband channel calibration using a vector network analyser

“…On the other hand, (Bories et al, 2005;Muqaibel et al, 2005) applied a calibration model after all measurements had been taken by the VNA. In (Bories et al, 2005), they measured the frequency domain UWB channels without calibration and applied calibration in the post processing.…”

“…In (Bories et al, 2005), they measured the frequency domain UWB channels without calibration and applied calibration in the post processing. In (Muqaibel et al, 2005), they used the calibration and post processing in their measurements. As a result their measured data must have been impacted by equipment and other cabling used in measurements setup.…”

Principle Component Analysis and Fuzzy Logic Based Through Wall Image Enhancement

“…However, antennas become large at low frequencies which restrict lower frequency range to 1 GHz practically. On the other hand, if we address detection through concrete walls, the upper frequency range is limited to 3 GHz [3].…”