Base-Station Random Placement Effect on the Accuracy of Ultrawideband Body-Centric Localization Applications

This letter presents an investigation on the effect of random placement of base stations on three-dimensional body-centric localization in the ultrawideband frequency range. Different base station configurations are studied (varied in xyz-axis, xy-axis, and z-axis direction), keeping the same range estimation error values as obtained from the body-centric localization experimental data in order to keep the main focus on the influence of the base-station configurations. It is observed that random positions of the base stations in the z-axis lead to higher localization error (3-8 cm) as the target nodes are spread out more in the z-axis direction. The localization error is analyzed in terms of geometric, horizontal, vertical dilution of precision (DOP), which is a measure of effectiveness of the placement of the base stations. For the DOP values (5-15), 1-3 cm error reduction is observed, and for higher DOP (>20) values, the error increases by 3-5 cm for short-range communication. Further analysis is carried out by varying the range estimation error in terms of mean value and standard deviation for evaluating the random base-station configurations, which also plays an important role in the accuracy of estimating the location of the target.