Performance Analysis And Simulation Verification Of Anti-blanketing Jamming For Satellite Navigation

Satellite navigation system has penetrated into various fields of politics,economy and military because of its high precision and high accuracy in positioning,navigation and timing service,which has become a hotspot in the world.In the military war,superiority in navigation is on behalf of the right to speak and the initiative.Studies have shown that the biggest threat to satellite navigation systems comes from the blanketing jamming,so to improve the system's anti-blanketing jamming is particularly important.In this paper,the LCMV algorithm based on the power inversion array and the space-time adaptive processing(stap)algorithm mainly focuses on the blanketing jamming.And then,the problem of large computational complexity encountered in the algorithm has been improved.The main work is as follows:First,the principle and type of blanketing jamming are introduced.Several special jamming signals are modeled and simulated.The time-domain waveform and power spectral density of the jamming signals are analyzed,and the jamming mode is described.Second,the anti-jamming algorithm plays a decisive role in the anti-jamming capability of the satellite navigation system.In this paper,the adaptive array structure and signal model are introduced,and an LCMV algorithm based on power inverted array is studied.The algorithm does not need to obtain the prior information of the signal and can adaptively form the nulling in the jamming direction.The experimental results show that it can distinguish the jamming signal spatially,and the depth of the null is deepened with the increase of the interference power,and at the lower drying ratio(10-30 d B)case,still has a good anti-jamming performance.Third,aiming at the shortcomings of the limitation of spatial filtering,the LCMV algorithm based on power inverted array is improved,and a space-time anti-jamming algorithm is proposed.The experimental results are given for the selection of the number of arrays,the number of intervals and the number of delay taps.And it is proved that when the number of antenna elements is equal to or less than the interference signal,the algorithm can accurately form the null in the direction of interference,without increasing the array antenna under the premise of greatly improving the degree of freedom in the airspace.Fourth,the space-time anti-jamming LCMV algorithm improves the anti-jamming performance of the system,but there is a matrix inversion and so on.With the increase of the data dimension,the complexity and computation of the system become unbearable.In this paper,a linear constrained multilevel Wiener filter is proposed.Based on this,the received data is dimensioned and the simulation experiment is carried out.The results show that the reduced dimension algorithm can effectively reduce the computational complexity under the premise of guaranteeing the stability of the system.