Multi-dispersive channel characterization for radio localization-based rescue search

This paper describes the results achieved by various experimental campaigns aimed at characterizing the directional propagation channel in DCS/UMTS band (1.9 GHz) in indoor and forest areas for similar antenna heights at both ends. These experimental results are useful in the context of pedestrian radio-localization systems relying on cell phone signals. Wideband data, are used to model the channel through various parameters: pathloss, shadowing, fading statistics, delay and azimuth-spreads. For indoor scenarios, path-loss exponents range from 1.4 to 2.2, while the shadowing, temporal K-factor, delay- and azimuth-spreads are found to be lognormally distributed. The RMS delay-spread ranges from 9 ns to 95 ns, whereas the azimuth-spread ranges from 20 to 140 degrees. In forests, the delay-spread, ranging from 60 to 120 ns, is strongly anti-correlated with the temporal coherence, and increases with transmit-to-receive distance. The azimuth-spread remains limited, with average values around 15 degrees.