Map Estimation Based On Doppler Characterization In Broadband Mobile Leo Satellite Communications

Due to the high relative velocity between mobile terminals and satellites, the broadband mobile LEO (Low Earth Orbit) satellite communication signals suffer a severe Doppler shift. Therefore, Doppler shift estimation would be one of the most important techniques to improve the performance of satellite communication systems. In this paper, a MAP Doppler estimator is proposed, exploiting a predictable Doppler characterization of the circular orbit LEO satellite and an OFDM (Orthogonal Frequency Division Multiplex) broadband signal structure with a CP (Cyclic Prefix). Simulations show that the proposed MAP algorithm outperforms the Doppler characterization estimator and CP-based estimator in both AWGN and satellite channels and robust to the velocity of terminals.