Research And Implementation Of Space-time Adaptive Anti-jamming Algorithm

Beidou satellite navigation system is a global satellite navigation which is independently construct and develop by our country.Its goal is to build an independent,open and compatible,advanced technology,stable and reliable navigation system which is covering the global.The system is to provide continuous,stable and reliable positioning,navigation,time services and the other related services for the worldwide users.The signal that BDS navigation satellite transmitted can transmit to the ground through the space.The power of the signal has been lower than the noise floor,which makes the signal of BDS can easily become the interference target,so that the information of location and the measurement will be influenced seriously by the interference.Therefore,studying some anti-jamming algorithms is needed for the receiver to deal with different disturbances,so that the BDS signal can be used without distortion.There are many types of interference in reality,mainly including human interference and non-human interference,in which the human interference mainly includes narrowband interference and broadband interference.In view of these human interference,some anti-jamming algorithms are studied.This paper is mainly studied in two aspects: one is narrowband suppression algorithm,the other is broadband interference suppression algorithm,and the convergence characteristics for each algorithm is analyzed in detail.Narrowband anti-jamming algorithm is simple,and also can suppress the narrowband interference well.It is mainly select the threshold detection algorithm,Kalman filtering algorithm and frequency-domain LMS algorithm as the narrowband anti-jamming algorithm research.Then the threshold detection algorithm is simulated and analyzed for the performance.At the same time,the broadband anti-jamming algorithm is used to suppress broadband interference,the anti-jamming algorithm against broadband interference is mainly the space-time adaptive filtering algorithm,and this paper is also studied the single satellite constraint and single star multi constraint anti broadband interference algorithm.Among them,the N-sigma algorithm in threshold detection algorithm is simulated by Matlab.The algorithm can suppress narrowband interference very well,and its anti-interference performance is analyzed,which proves that its anti-interference effect is very good.At the same time,the space-time adaptive filtering algorithm is simulated by Matlab.The algorithm can suppress broadband interference very well,and its anti-interference performance is analyzed,which proves that its anti-interference effect is very good.Finally,in the full introduction of various algorithms,this paper introduce the design of hardware scheme which is based on the Matlab software platform.It introduce the implementation scheme which is based on the space-time adaptive filtering algorithm.The hardware is mainly to set up based on the ARM+FPGA,and in the end,it summarizes and analyses the factors and the influence of anti –jamming performance.