Research On Coverage Area Division And Beamforming For Multibeam Antenna

This paper focuses on the coverage area division and beamforming for the multibeam antenna technology of the low earth orbit(LEO)satellite communication and indoor communication.The main work and research results of this paper are as follows:The LEO satellite has a large communication angle,resulting in a large difference in path loss at different angles.The existing multi-beam coverage area division method cannot meet the coverage requirements of effective isotropic radiated power(EIRP)in the considerable angle areas.Therefore,this paper proposes a method for dividing the beam coverage area from the outside to the inside,combined with the subarray multi-beam forming.Under the condition of meeting channel consistency,it achieves the optimal coverage of a large range of multi-beams with equal flux to the ground,which greatly improves the overall efficiency of existing beam-forming methods.At the meantime,a clustering color separation algorithm and a frequency reuse color separation algorithm based on depth first search(DFS)are proposed to solve the problem of low mutual interference color separation among non-uniform multi-beam.This paper has completed the beamforming coverage research for LEO satellite.52 transmit beams with 12-color frequency reuse are designed to cover ±55° areas.The edge EIRP of a single beam is not less than 25.5 d BW and the carrier-to-interference ratio(C/I)is not less than 16 d B.Indoor communication,such as Lamp Site EE(Enterprise Edition)proposed by the Huawei corp,is moving towards intelligent mobile communication.This paper presents a dynamically adjustable indoor coverage scheme.Based on beamforming algorithms,such as Woodward-Lawson synthesis method and differential evolution(DE)algorithm,the main lobe width of the multi-beam can be adjusted.Based on robust LCMV,a wide null-notch beam can be obtained.The need of indoor network coverage is met which have the characteristics of a flexible system,software control,and flexible expansion.This paper has completed the beamforming coverage research for indoor network.The multibeam antenna which can perform cell merging,splitting and dynamic adjustment in real time is designed.Cell lobes are subdivided into 4 levels of angle 30,40,60 and120.The main lobe gain fluctuation is less than 3 d B.