Wideband propagation measurements and results at L- and S-bands for personal and mobile satellite communications

The effects of the propagation channel have a major part to play in the design and development of mobile satellite communication systems. These effects vary with respect to the elevation angle of the satellite to the user. In the past decade, many propagation studies by various organisations, have addressed the effects of signal attenuation with respect to elevation angle and user environment. However, there is very little data on the effects of wideband parameters with respect to elevation angle. These can be very important in characterising the channel for hand-held terminals in future satellite PCN systems. A wideband propagation study applicable to satellite-based mobile vehicle mounted and hand held communication systems at L- and S-bands has been carried out by the CSER at the University of Surrey around the Guildford area. Simultaneous measurements were carried out during the summer months of 1995 at L-band (1540-1560 MHz) and S-band (2315-2335 MHz). The frequencies allocated by the Radiocommunications Agency being as close as possible to the bands that have been allocated for mobile satellite communications, without causing interference to other users, given the bandwidth required (20 MHz), for the channel sounder. The transmissions were radiated from a helicopter acting as an alternative platform simulating a satellite. A Robinson R22 helicopter and a Bell Jet Ranger helicopter was used during the measurement campaign.