Research On Beidou Forwarding Deception Interference Detection Technology

With the rapid development of China's Beidou navigation system and its wide application in military and civilian fields,the problem of Beidou user receivers being susceptible to interference has become increasingly prominent.This is mainly because the satellite signal power is weak,resulting in poor anti-interference ability of the user receiver,making the receiver susceptible to natural interference and human interference.Natural interference,although we cannot avoid it,the threat of human interference is more serious.Human interference to the receiver,including suppressed interference and deceptive interference.The suppression power of the suppression interference is large,and it is easy to be detected during the implementation process,so the space for the suppression interference is getting smaller and smaller.However,deceptive interference is transmitted by transmitting the same or similar signals as real satellite signals,enticing the other party's misunderstanding and using the obtained navigation information to locate,which makes it difficult for the receiver to detect such interference.Therefore,deceptive interference has gradually become important threats to satellite navigation systems.Among them,the threat of forward-style deception jamming is greater,which not only can interfere with civilian signals,but also can cause interference to military navigation signals.In order to improve the anti-interference ability of the receivers of Beidou users in China,this paper takes the forward-style deception jamming detection technology of Beidou signal as the research content.The main work and achievements are as follows:1.The paper studies the structure and characteristics of the Beidou satellite signal and analyzes the vulnerability of the Beidou signal,which is highly susceptible to interference.The deceptive interference is classified and summarized,and the signal characteristics and interference principle of the forward-style deception jamming are analyzed.The deep understanding of the forward-style deception jamming is the basis of the interference detection.2.According to the signal characteristics of the forward-style deception jamming,the interference detection algorithm based on the signal acquisition phase is deeply studied.The paper analyzes the influence of the forwarded spoofing signal on the receiver signal acquisition.Based on this,the correlation peak detection algorithm is studied and optimized.Aiming at the limitations of the optimized correlation peak detection algorithm,a FWHM detection algorithm is proposed.The interference detection algorithm for hourly deception signal is analyzed.At the same time,in order to improve the detection precision of FWHM,the selection of the main point sampling discrete point fitting function is analyzed.Finally,the deception jamming detection scheme in the signal acquisition stage is designed according to the hierarchical relationship of the algorithm.3.In order to improve detection probability and avoid missed detection in single detection,the deceptive interference detection algorithm based on the signal tracking stage is designed after the interference detection is completed in the signal acquisition stage.Using the Doppler feature of the spoofing signal,the deceptive interference detection method under the single-star Doppler shift and multi-star Doppler rate-of-change monitoring is studied.When the receiver tracks the spoofed signal by the navigation signal,the interference detection algorithm based on signal Doppler shift is deeply studied for the possible Doppler hopping characteristics and analyze the method of selecting threshold values and the probability of detecting fraudulent interference.According to the characteristics of the same interference source from the deception signal,as the complement of the Doppler mobile variance detection algorithm,the interference detection algorithm under the multi-star Doppler rate uniformity monitoring is studied.Finally,combined with the deception jamming detection method in the signal acquisition phase,the overall strategy of deception jamming detection is proposed.4.The performance of the algorithm is verified by the experiment,which mainly includes the detection performance testing in the signal acquisition and tracking stages.The detection experiments under different spoofing interference scenarios are designed and the relationship between detection probability and spoofing signal forwarding delay and power amplification factor is given.The results show that the detection probability is higher with the increase of spoofing signal power and forwarding delay.When the spoofing forwarding delay is 1 chip,the detection probability reaches 80%,and when the forwarding delay exceeds 2 chips,the detection probability reaches 100%.The detection power of the spoofing signal is increased by 3dB relative to the navigation signal by 92.4%,and the detection probability of increasing 6dB is 100%.The tracking phase simulation experiment verifies the effectiveness of the Doppler shift detection algorithm and the Doppler rate uniformity detection algorithm.The results show that the deceptive signal can be identified in time and effectively by monitoring the Doppler variation of the received signal after the receiver is deceived.Finally,through the joint detection experiment of two parts,it is verified that the joint detection algorithm based on the Beidou signal acquisition and tracking stage designed in this paper can effectively reduce the miss detection of single detection,which can greatly improve the detection performance of the receiver on the forward-style fraud signal.