Research On Technologies Of Satellite Navigation Receiver Anti-jamming

Satellite navigation technology has penetrated into people's daily life and the construction of national defense economy,such as mobile phone navigation applications in life and precision guided weapons in military.Satellite navigation system as a national important information infrastructure,has the vital significance to safeguard national security and has been an important symbol of comprehensive national strength.Therefore,many countries in the world are developing their own satellite navigation system.In this thesis,Global Positioning System(GPS)is taken as an example to study the anti-jamming technology of satellite receiver.The satellite navigation signal arriving at the ground satellite receiver is very weak and buried in the noise,which causes the satellite navigation signal to be vulnerable to various kinds of human interference and non-human interference.This may lead to the failure of the follow-up signal acquisition and tracking.Therefore,the anti-jamming of the satellite navigation signal is the necessary work of the satellite navigation receiver.The anti-jamming processing is an important part of the satellite navigation receiver and the performance of the anti-jamming algorithm determines whether the satellite navigation receiver can effectively suppress the interference signal.Therefore,the study of anti-jamming algorithm is very important.Firstly,this thesis analyzes the main jamming modes of the satellite navigation receiver and introduces a variety of anti-jamming strategies.Secondly,the thesis introduces the GPS navigation signal and its generating principle,and discusses several adaptive anti-jamming algorithms,such as Gauss-Newton,Least Mean Squares(LMS),Recursive Least Squares(RLS),and Multistage Nested Wiener Filter(MWF).The simulation results indicate that these anti-jamming algorithms both have advantages and disadvantages.Then,according to the deficiency of the Gauss-Newton adaptive algorithm,it is improved and simulated with realizing the balance between convergence speed and steady-state error.Meanwhile,based on the characteristics of narrowband interference in satellite receiver,a new implementation method of narrowband interference suppression is proposed,which is the parallel double time domain interference suppression method IIR-FIR.The simulation results indicate the method not only can suppress the signal carrier interference,but also can effectively suppress the narrowband interference signal with a certain bandwidth.Finally,based on wideband interference signal,the expression of space-time signal is illustrated.Simultaneously,the linear algebra basis of space-time subspace projection method is also introduced.Then,according to the disadvantage of the fixed series subspace projection method,the improvement is made,which is a subspace projection method based on Fast Fourier Transformation(FFT)estimation of forward decomposition series.The simulation results indicate that the proposed method can effectively estimate the forward decomposition series and suppress the wideband interference signal.