Characterization of on‐human‐body UWB radio propagation channel

Abstract

AbstractWireless body area network (WBAN) has begun to receive attention recently. Ultra wideband (UWB) is a promising technology for WBAN applications. This article presents the results of UWB radio channel measurements performed on human bodies from 3.1 to 10.6 GHz in indoor environments. The measurements were devised to generate the radiographs of path loss and delay spread for the first time. The radiographs contain both qualitative and quantitative information on the channel. They clearly display the influence of the body on the channel and thus reveal where the network nodes should be strategically placed on the body in the design of the UWB WBAN systems. They directly give such channel parameters as path loss and delay spread. They also reflect variations of the channel on and in close proximity to the body. In addition, the measurements were made in an anechoic chamber to expose the impact of the body and to study the effect of different environments on the channel. It is shown that for the UWB channel on the body the path loss exponent n = 2.7 can be used, while for the UWB channel through the body the path loss exponent increases to n = 3.7. The maximum value of the rms delay spread is 12 ns. The rms delay spread values are less than 6 ns 50% of the time. The number of multipath components increases with the separation between transmit and receive antennas. Because of the nonreflecting mechanism, the path loss is larger and the delay spread is smaller in the anechoic chamber environment. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1365–1371, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22411