LEO Satellite Multibeam Coverage Area Division and Beamforming Method

The low-orbit satellite has a large communication angle, resulting in a large difference in path loss at different angles. The existing multibeam coverage area division method cannot meet the coverage requirement of the effective isotropic radiated power (EIRP) in these large-angle areas. Therefore, this letter proposes a method for dividing the beam coverage area from the outside to the inside. Combined with the subarray multibeam forming method, it achieves the optimal coverage of isoflux multiple beams to the ground with unchanged output power of the transmitter, which greatly improves the overall efficiency of existing beamforming methods. At the meantime, a frequency reuse color separation algorithm based on the depth first search is proposed to reduce the mutual interference among nonuniform multiple beams. As an example, 52 beams with 12-color frequency reuse are designed to cover ±55°. The edge EIRP of a single beam is no less than 25.5 dBW and the carrier-to-interference ratio is no less than 16 dB.