A Comparison of Outdoor-to-Indoor Wideband Propagation at S-Band and C-Band for Ranging

Indoor positioning using mobile radio signals at different frequency bands has gained remarkable attention. Thus, evaluating the influence of the radio propagation channel at different carrier frequencies with respect to the ranging performance is of interest. This paper presents a measurement-based comparison of the outdoor-to-indoor wideband propagation channel at S-band and C-band. We evaluate channel parameters that have an impact on the ranging and, in turn, on the positioning performance. Our comparison is threefold and is based on large-scale channel parameters, ranging performance, and spatial characteristics of the channel. In the first set of comparisons, we consider received power, power delay profile (PDP), delay spread, mean delay, and a number of multipath components (MPCs). The second set of comparisons considers ranging performance: Both the correlator-based and recursive-Bayesian-filter-based ranging estimators are evaluated using the measurement data. In the third set of comparisons, spatial characteristics of the propagation channel at S-band and C-band are compared and analyzed for range estimates to provide an insight for positioning applications.