Research on Methods for Interference Suppression in Satellite Internet

Aiming at the impact of Low Earth Orbit (LEO) satellite constellation interference to the downlink of Geosynchronous Orbit (GEO) satellites in Satellite Internet, this paper proposes interference suppression methods for terrestrial terminals based on signal processing. The overall operational process is divided into three parts, namely, high-resolution spatial filtering, interference margin estimation, and interference suppression algorithm. Firstly, an improved multiple signal classification (i-MUSIC) algorithm is used in spatial filtering to solve the problem of heteroscedasticity. Secondly, the interference margin of the receiver is defined combined with satellite link characteristics. It provides the prerequisite for an interference suppression algorithm. Next, the symbol weight extensive cancellation algorithm in the frequency domain (FD-SW-ECA) based on Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) is proposed to suppress the co-frequency interference. The simulation results show that using the proposed methods in this paper can significantly reduce errors, and the FD-SW-ECA algorithm is effective for interference suppression.