Angle Partition-Based TDMA for VDES Satellite Multiuser Downlink Communications

As an important role in achieving seamless world-wide coverage for the maritime communication, the VDE satellite component (VDE-SAT) aims to provide efficient services to a large number of ship terminals each with only a limited satellite coverage time, which requires efficient resource allocation strategies. In this paper, we investigate the downlink VDE-SAT system consisting of a low-earth orbiting (LEO) satellite communicating with multiple randomly distributed ship terminals. As the LEO satellite orbits the Earth at a fixed altitude and speed, ship terminals are served in a periodic manner with known but periodically time-varying channel gains from the satellite. By exploiting the periodic channel gain variations in the line-of-sight (LoS) dominant satellite-ship channels, we propose an angle partition based time division multiple access (TDMA) scheme to schedule downlink communications from the satellite to ship terminals based on the moving satellite's real-time position. Specifically, time resources allocated to different ship terminals are optimized via the partition of the satellite's azimuth angle range to maximize their minimum/common throughput. Simulation results verify the effectiveness of the proposed angle partition-based TDMA scheme and show its performance improvement over benchmark schemes.