Research On Anti-interference Technology Of GNSS Space Frequency

The global satellite navigation system is widely used in military and civil fields,and the dependence of the global satellite navigation system is increasing.However,when the satellite navigation signal is transmitted to the ground,the power is only-133dB,which leads to the satellite navigation signal is easy to be disturbed by the outside,and the GNSS receiver is very sensitive to intentional or unintentional interfrence.This characteristic can reduce the accuracy and reliability of the receiver.Therefore,it is very necessary to study the anti-jamming technology of satellite navigation to improve the accuracy of the satellite navigation signal.This paper studied traditional space frequency anti-jamming technology(SFAP)and its basic theory,and the processing idea of variable step size frequency domain block LMS algorithm(FBLMS),has been a new space frequency anti-jamming algorithm,improve the anti-interference performance of the traditional algorithm:Firstly,the principle of time domain block LMS algorithm is analyzed,and the parameters of the performance of the algorithm are simulated.Secondly,the frequency domain block LMS algorithm with fixed step size is studied and completed.Also of some variable step size the FBLMS algorithm are analyzed and The comparison of these algorithms under different ambient noise is carried out.Experimental results show that the variable step size algorithm has better convergence performance.Then,the principle and the criterion of the traditional space frequency anti-jamming technology are described in detail in this paper.According to the idea of variable step size FBLMS algorithm,based on the traditional SFAP technology,a variable step size SFAP algorithm is proposed,and the convergence of the improved algorithm is proved.In this paper,the improved algorithm is simulated,and the results show that the improved algorithm can effectively suppress the interference signal,and the anti-interference ability of the GNSS receiver is improved.Finally,the improved SFAP algorithm and the traditional algorithm are simulated and compared.The results show that the improved algorithm has better convergence performance and anti-interference ability than the traditional algorithm under the same input conditions.