On the Effect of Antenna Height on the Characterization of the Indoor UWB Channel

Ultra-wideband (UWB) technology is being proposed for several short range wireless applications. Some of the applications, such as position location devices for rescue personnel, may require the antenna height to be close to the ground. In scenarios where the antenna height is very low (from 0 to 30 cm), propagation characteristics and channel modeling are needed to provide important insights for the application design. This paper presents time-domain measurements and channel characterization of the indoor UWB channel at three different antenna heights (7.5 cm, 26.5 cm, and 108.5 cm). The transmitting and receiving antennas are placed at heights referred to as near ground, middle ground, and above ground. The effects of the antenna height on the channel characteristics are analyzed. Both large and small-scale characteristics are evaluated and the results for different antenna heights are compared. The results show that large scale characteristics exhibit monotonic behavior with respect to antenna height while small scale characteristics do not follow this behavior. The possible explanations for the obtained results are also discussed.