Performance analysis of diversity techniques for secure SATCOM-on-the-move systems

In secure satellite communication (SATCOM) on-the-move (SOTM) systems often multiple antennas are carried within one military convoy as stand-by redundancy. As an alternative, in this paper the operation of all SOTM antennas in the convoy as a diversity system is analyzed and evaluated using real measured data. Multiple SOTM antennas allow the application of antenna selection (AS) and maximum ratio combining (MRC) in the receive case. If the SOTM terminal with multiple antennas acts as transmitter (Tx), beamforming, AS, and space-time coding could be applied to achieve Tx diversity. All strategies are able to enhance the coverage of the SOTM system depending upon the distance between the antennas. Different forms of available channel state information (CSI) affect the bandwidth efficiency of the diversity system. AS is found to be an appropriate candidate for maximizing the coverage without much effort.