Frequency-Dependent UWB Channel Characteristics in Office Environments

This paper reports frequency-dependent ultrawideband (UWB) channel characteristics. Measurements were performed in 103 receiver locations of six different office environments. From the measured data, the effect of frequency on the path-loss properties of a UWB signal is analyzed. After analyzing the path-loss behavior to propagation environments, the path-loss exponent variation models are developed in various environments as a function of frequency. Based on these models, path-loss prediction is performed, and the accuracy of the prediction is compared with those of existing path-loss models. In addition, the frequency-dependent UWB channel correlation characteristics are investigated. For the frequency correlation statistics of the UWB channel, double-slope models representing correlation coefficients are established with and without line-of-sight (LOS) paths. Using these correlation models, a channel gain estimation algorithm is proposed. The performance of the proposed estimation algorithm is evaluated with estimation parameters, and it is confirmed that the proposed estimation algorithm has better performance than the conventional algorithm using a linear interpolation algorithm.