SOTM Measurements for the Characterization of the Wideband Mobile Satellite Channel at Ku-Band

Satellite communication-on-the-move (SOTM) systems provide high throughput communications at frequencies in the Ku-band or above over a geostationary satellite using continuously tracked directive antennas. The narrowband wireless channel for SOTM applications has been thoroughly investigated with respect to its fading behavior. The focus of this paper is on the wideband characteristics of the SOTM channel and addresses the question whether the channel is either flat-fading or frequency-selective due to multipath propagation. Results of a measurement campaign in the Ku-band for the fading properties, the Doppler spread, and the power delay profile of the channel are presented. A novel in-depth analysis of the measurement results collected in a bandwidth of 10MHz showed no evidence for the existence of relevant multipath components that would cause a frequency-selective channel. Finally, a theoretical discussion on the conditions for a possibly frequency-selective channel is shown. It is concluded, that in some rare special cases the considered SOTM channel could be affected by multipath signal components.