Research And Implementation Of Robust Algorithm For Navigation Anti-interference

With the rapid development of Global Navigation Satellite System(GNSS),robust navigation and anti-jamming algorithm has become the key research direction in high dynamic environment.The directions of arrival(DOA)of interference changes rapidly and transiently.This will cause the exact direction of arrival of interference and the nulls produced by conventional anti-jamming algorithm mismatch,which will lead to degrading or even invalid completely to the performance of anti-jamming algorithms.Therefore,it is of great significance to study the robust navigation anti-jamming algorithm in high dynamic environment.In this thesis,two kinds of nulling widening algorithms based on covariance matrix taper(CMT)are studied,and the nulling widening algorithm combined with power inversion algorithm or digital multi-beam anti-jamming algorithm is used to study the change of the robustness of the anti-jamming algorithm.Firstly,this thesis deduces the null widening algorithm based on Gaussian distribution and Laplace distribution in detail under the condition of the space-time structure and uniform circular array.Then the null widening algorithm and the power inversion algorithm is combined to study the influence of the different system variables on the jamming performance which will provide the theoretical basis for the selection of parameters for hardware implementation.The simulation results show that the two kinds of nulling widening algorithms can expand the null width around the direction of arrival of interference,and have good adaptability to the situation that DOA changes rapidly but the conventional power inversion algorithm has greater Signal to Interference plus Noise Ratio(SINR)and better anti-jamming performance when the direction of the interference is constant.Secondly,this thesis unites the null widening algorithm and the digital multi-beam algorithm together.It also simulates and analyzes the impact of the performance of the anti-jamming algorithm against the interference of different system parameters.It can be seen from the comparison of simulation results with the power inversion algorithm that the null widening algorithm does have null broadening effect in the direction of interference,and has good adaptability to high dynamic environment.Under the same null-widening condition and the same interference environment,the anti-interference performance of the digital multi-beam algorithm has better anti-jamming performance than the power inversion algorithm.Finally,this thesis introduces the overall structure of the navigation anti-interference system and the matrix inverse algorithm.Then the paper introduces the covariance matrix module,and covariance matrix taper module in details which is closely related to the null widening algorithm with designing method and parameters.Simulation verification was performed,and then the receiver platform was measured to verify the correctness of the algorithm.The simulation results and the measured results of this paper show that the algorithm studied in this paper has a certain degree of innovation and practicality.