Smart antenna system and its application in low-earth-orbit satellite communication systems

Space-division-multiple-access is one of the solutions for increasing system capacity as well as improving system performance in wireless communications. Experimental studies have been reported, using a smart antenna system to exploit spatial diversity in low-earth-orbit (LEO) satellite personal communication services (S-PCS). The paper presents direction-of-arrival (DOA) estimation of satellite signals, variation of spatial signature and DOA with frequencies, elevation angle and motion, and diversity gain achieved by using an antenna array in line-of-sight (LOS) and shadowing scenarios. For typical environments, such as LOS and light or heavy shadowing cases, the experimental results reveal rich spatial diversity and high diversity gain when using a smart antenna system in LEO S-PCS.