Beam Pointing Optimization Based Downlink Interference Mitigation Technique Between NGSO Satellite Systems

This letter proposes a novel interference mitigation technique for spectral coexistence between large-scale non-geostationary orbit (NGSO) satellite systems by optimizing satellite antenna beam pointing. Firstly, a dynamic exclusion zone of NGSO satellite antenna beam pointing is defined. Secondly, we transfer frequency compatibility problem between NGSO systems into a constrained nonlinear multivariate optimization problem considering the joint effect of link distances as well as angles between links and solve it using Genetic Algorithm (GA). Then we select actual working parameters of Starlink and OneWeb satellite systems to verify the effectiveness of proposed interference mitigation technique in the worldwide. The available time of the interfered system is up to 98.5% of total simulation run time after interference mitigation. The results show that the proposed interference mitigation technique can effectively mitigate the interference between NGSO satellite systems and guarantee signal to interference plus noise ratio (SINR) at the interfered earth station.