Among various indoor positioning technologies, impulse-radio UWB is a promising technique to provide indoor positioning and tracking services with high precision. Because UWB regulations turned to imposing restrictions on UWB low band, UWB high band becomes attractive for enabling simple and low cost implementation. However, UWB high band endures much larger propagation loss than UWB low band. In this paper, we propose two separated methods to compensate the deficiency of high band in propagation. With the first method, we bundle several IR-UWB modules to increase the average transmission power, while an adaptive detection threshold is introduced at the receiver to raise receiving sensitivity with the second method. We respectively implement each of these two proposed methods and evaluate their performance through measurements in laboratory. The results show that each of them achieves about 7dB gains in signal power. Furthermore, positioning performance of these two proposed methods are evaluated and compared through field measurements in an indoor sports land.

An analysis is carried out about the reflection influence on the microwave attenuation measurement for moisture content determination. A new method taking into account the reflection influence is proposed and it is proved valid by the experiment results. Using this method, the density dependence of the attenuation is measured and the measured data can be fitted well by a straight line passing through the origin. Therefore, the attenuation per unit density and propagation distance is a function which depends only on the moisture content and the function is useful to the determination of the moisture content.