Experimental studies of using a smart antenna system in low-Earth-orbit satellite communications

Space division multiple access (SDMA) is one of the solutions for increasing system capacity as well as improving system performance in wireless communications. A series of experimental studies using a smart antenna system to exploit spatial diversity in terrestrial communications have been reported previously. However, using a smart antenna system and SDMA in the satellite-Earth propagation channel is another interesting topic for wireless communication. Estimates of the direction-of-arrival (DOA) of a satellite signal, studies of the variation of the spatial signature with frequencies, satellite location and motion, and diversity gain achieved by using an antenna array in both line-of-sight and shadowing scenarios are presented in this paper. For a typical environment of both line-of-sight (LOS) and shadowing cases, the experimental results show rich spatial diversity and diversity gain when using a smart antenna in low-Earth-orbit (LEO) satellite mobile and personal communications