SUMMARY
One of major problems with LEO/MEO is the high speed of these satellites relative to mobile terminals. Therefore, efficient and accurate methods are needed for satellite tracking and handovers between the moving footprints produced by the satellite multibeam antennas. In this project, we propose an accurate antenna pointing system (APS) for the satellite tracking and an efficient strategy for the handovers in the satellite networks.
We have investigated the performance of the APS system with respect to the turning speed of the mobile terminal, the antenna radiation patterns and the application of a dithering mechanism. Analytical and computer simulated results indicate that our antenna pointing system is feasible for a given worst-case mobility scenario and can provide an effective satellite tracking.
The handover strategy assumes that the mobile terminal has dual receivers to simultaneously search the pilot signals from two adjacent beams. In this way, an independent complex global positioning system for the mobile user is not needed. The performance of the above handover approach is studied in terms of static and dynamic channel allocation strategies.