Satellite Channel Impairment Mitigation by Diversity Techniques

This paper investigates satellite-MIMO, space-time coded for diversity gain. Whereas a dual satellite to single antenna terminal link provides shadowing and some multipath diversity gain, a dual antenna terminal provides additional multipath diversity gain. This gain is demonstrated by simulating high resolution time series channel data for urban and highway environments, for SISO, MISO and MIMO systems, and with uncorrelated and correlated shadowing, and applying it to a bit error rate system simulator using Alamouti space-time coding. Bit error rate curves for each case are provided showing the benefit of 2x2 MIMO over 2x1 MISO. It is shown that 2x1 MISO diversity gain over shadowing (shadow correlation dependent) and multipath diversity gain is of order two (N=2), whereas in the 2x2 MIMO case, diversity gain over shadowing is still of order two but diversity gain over multipath is now of order four (N=4). Methods for investigating shadowing correlation and availability are also given.