Research On Adaptive Anti-jamming Algorithm Of Beidou Navigation Joint Domain

With the development of anti-jamming technology of satellite navigation,multi-domain adaptive processing has become a trend.Classical anti-jamming methods operating in time domain,frequency domain,space domain and space-time domain are based on the scalar array,wherein the degrees of freedom are limited.Due to the right-handed circular polarization of the navigation signal,the polarization-sensitive array utilizes polarization domain information and provides a new solution of anti-jamming.This paper focuses on the application of polarization-sensitive array in navigation anti-jamming technology.The main work includes:1.The anti-jamming performance of a single dual-polarized antenna is studied.It can effectively suppress a single-frequency interference or wideband interference taking the advantage of occupying only one single antenna position.When extending to antenna array,the polarization-space adaptive processing is also studied.The influences of the number,elevation angle and polarization information of interferences on anti-jamming performance is also presented.Compared with the scalar array,the increased degrees of freedom leads to better filtering performance.Then the influences of array mutual coupling and channel mismatch on the performance of polarization-sensitive array filtering are analyzed.2.The space-time-polarization anti-jamming algorithm is studied to further improve the degrees of freedom.The influences of both the number of interferences and the delay unit on anti-jamming performance are analyzed,compared with the polarization-space anti-jamming algorithm,the signal-to-interference-plus-noise is increased by 6dB in the same array aperture.To reduce the computational complexity of the joint three-dimensional processing,the reduced-rank algorithm of joint iterative optimization based on recursive least square(RLS)is studied.It can not only reduce the computational complexity but also improve the convergence speed.It also keeps robust to the selection of the rank-reduction dimension.3.The robust anti-jamming algorithm of polarization-sensitive array is studied.This algorithm based on eigen-decomposition increases the depth of nulling,which extends the applicability in the environment when the interference power is non-stationary.The performance of the algorithm under single-frequency and wideband interference is verified.