Detection Of Sweep Interference Signal In GNSS Receiver

Satellite navigation has been widely used in various fields,such as modern war,land and air three-dimensional war in the military,and transportation,car navigation,land mapping,disaster relief etc in civil field.The real-time and accuracy of navigation information is more severe in electronic warfare,war of resistance against aggression,weapon guidance.Timely anti cheating and anti interference can guarantee the high precision of the system,so anti jamming detection has become the key technology of navigation and the requirement is higher and higher.Anti jamming technology can be strengthened from the signal system,antenna receiver and other aspects,but this paper studies the receiver anti-jamming technology.In this paper,the anti-jamming technology is based on the traditional time-frequency analysis,a new method is proposed to detect the sweep interference signal in the receiver based on Wigner-Hough transform.Using traditional time-frequency analysis methods,the short time Fourier transform or the spectrum will appear the contradiction of the time frequency resolution,and the Wigner-Ville transform has the cross term.By comparison with these methods,it is shown that the Wigner-Hough transform can solve the problem of time frequency resolution and cross term,which can effectively improve the time-frequency aggregation,restrain the cross term and noise.In addition,this paper also puts forward a new algorithm of Karhunen-Loeve transform,it introduces the principle of the algorithm,the signal is expanded into a series of uncorrelated sequences and the feature of the signal is extracted,finally the swept frequency signal is reconstructed in the subspace.The simulation results verify that the Karhunen-Loeve transform can detect the frequency of weak signal and different noise environments.