An Interference Mitigation Method via Variable Separation Angle between LEO Constellations

With a large number of satellites in orbit, there is an inevitable problem of co-frequency interference between low earth orbit (LEO) satellite constellations. However, existing studies tend to focus on avoidance strategies with a constant angle, ignoring the positional relationship between satellites and earth stations. In this paper, our work is to study the interference mitigation strategy between LEO constellations and propose a variable separation angle method based on different positional relationships while selecting the optimal separation angle in each case. Moreover, given the satellite capacity, the joint optimal problem of minimum separation angle and maximum channel capacity is established and solved by the whale optimization algorithm (WOA) for its better convergence speed and stability with respect to other algorithms. Meanwhile, the separation angle strategy is applied to interference simulation based on Oneweb and Lightspeed. Compared to the fixed separation angle strategy, the simulation results prove the method improves the system performance in terms of interference power, information rate, and interference time.