Phase measurements in a satellite-mobile channel

Land mobile satellite systems (LMSS) are to be implemented in several parts of the world providing a wide-coverage communication system. Propagation experiments have been carried out in order to characterize the channel and help in designing the system and equipment. The amplitude characteristic is usually the main objective of these experiments, because channel availability and margins are determined by it. However, phase characteristics are important for designing the receiver carrier synchronizer, and to determine the feasibility of coherent communications in this channel. Phase characteristics of the signal received in an LMSS propagation experiment are described. The experiment was carried out in the framework of PROSAT-II of ESA. The effect of several propagation factors on the phase sequences have been analyzed both in time and frequency domains, showing the implications for system and receiver design