Theoretical and experimental characterisation of the satellite-to-indoor radio channel

Personal communication systems play more and more important role in the everyday life. However, there are some constraints that are difficult, or perhaps impossible to overcome with these terrestrial communications systems. One of the most viable solutions is the use of satellite personal (mobile) communication systems (S-PCS) to provide communication between two points that are located anywhere on the surface of the Earth. These systems apply low Earth orbit (LEO) satellites, this fact and that the small-sized mobile terminal in these systems uses small, omnidirectional antennas make the propagation channel of the S-PCS systems a rather harsh medium, with severe multipath propagation effects and Doppler shifts. The difficulties are even more pronounced if the propagation takes place partially in indoor environments. In order to make these systems as less sensitive to the hostile channel as possible we have investigated the basic characteristics of the propagation channel. The indoor channel is examined. A general model for the satellite-to-indoor channel is introduced for simplifying the analysis, then the experiments made by a helicopter are described. The measurement results are shown in graphical formats, and the analysis of the measurements, as well as some conclusions are discussed.