Research On Satellite Interference Source Location And Interference Suppression Technology

To solve the interference problem in satellite communications, we must make full use of the anti-jamming technology in time domain, frequency domain or space doamain. Relative to the time and frequency domain, the space doamain anti-jamming has become an important measure in interference suppression. In order to eliminate the malicious and involuntary interference signal of radio frequency, we can combine the interference source localization technology and satellite adaptive array beamforming technology, and achieve high performance of spatial filtering. There is a key problem to realize the spatial filtering: how to quickly locate the interference signal and adjust the beam gain to zero in the direction of interference sources. In this background, this dissertation investigates the satellite interference sources location and interference suppression technology from two aspects: one is to estimate the location of the interference sources from the ground; the other is to use the adaptive array digital beamforming technology(ADBF) to suppress or eliminate the interference on the basis of the location. There is a new way of the satellite interference sources location which uses the multi-beam cover characteristics of satellite antenna to achieve high-precision and high-resolution localization of the interference sources with single satellite. We can use the spatial spectrum estimation technique to estimate the direction of arrival(DOA) of interference sources based on the signal from satellite antenna array, and then according to the ephemeris information, we can get accurate ground interference sources of information. Using multi-beam cover characteristics of satellite antenna is able to realize the interference sources location, at the same time, it also laid a foundation for the adjusting zero of satellite adaptive antenna array.In this dissertation, in allusion to the DOA estimation algorithm based on of the narrowband coherent source signal model, we propose two improved 2-d MUSIC estimation algorithm and 2-d ESPRIT estimation algorithm, both of which have the decoherence ability of coherent signal, and the estimation performance of the proposed algorithms for 2-d DOA estimation of coherent signal are analyzed by simulation. We also study the DOA estimation algorithm of the wideband coherent source signal model, and propose a method to realize coherent 2-d DOA estimation algorithm based on angle frequency separation for broadband focusing, and the algorithm can be applied to arbitrary planar array geometry structure. On the basis of DOA estimation, we use the adaptive digital beamforming algorithm to suppress the interference, and propose a modified eigenspace-based multi-beam constrained minimum variance(MEMBCMV) algorithm. The output SINR of the algorithm is increased, and it also has the fast convergence speed and good performance under less snapshots. The algorithm is very robust.