Research On Satellite Navigation Anti-jamming Technology Based On Multi Domain Fusion

Satellite navigation systems are becoming more and more widely used in both civil and military applications,and their susceptibility to interference is becoming more and more prominent.Since the anti-interference techniques in time domain,frequency domain and air domain can only suppress narrowband interference signals,the antiinterference effect on broadband interference signals is not obvious,so in order to improve the working ability of navigation receiving system under various kinds of interference,this paper studies the anti-interference techniques of air-time and airfrequency fusion.Its main research content includes the following three parts:Firstly,this paper briefly describes the principle of satellite navigation receivers,introduces several basic receiving antenna formations,GPS signals and interference techniques for receivers,analyzes the advantages and disadvantages of time-domain,frequency-domain and air-domain anti-jamming techniques,and thoroughly studies and compares several optimal guidelines for adaptive filtering.Then,the anti-jamming technique of space-time fusion processing is studied for the respective shortcomings of time domain,frequency domain and air domain antijamming techniques.It is a two-dimensional processing model of air-time fusion by adding time-domain filters under the model of air-domain anti-interference technique,and the power inversion adaptive algorithm under this model is investigated.An improved power inversion algorithm is studied for the shortcoming of the power inversion algorithm under the air-time anti-interference technique for the lack of zero trap depth generated by the interference signal.And on the basis of this,we simulate the suppression ability of the space-time anti-interference technique for narrowband and wideband signals respectively,and also explore the influence of the interfering signal power,different delay units and the number of array elements on the anti-interference ability of the space-time anti-interference technique under the improved power inversion algorithm,and verify that the space-time anti-interference technique has more degrees of freedom than the space-domain anti-interference technique.Finally,the anti-interference technique of air-frequency fusion processing is studied.Similar to the air-time anti-interference technique,a two-dimensional processing model of air-frequency fusion is formed by adding a frequency domain processing structure under the model of air-domain anti-interference technique,and the LMS and SMI adaptive algorithms under this model are investigated.Then the convergence performance of the two algorithms is compared,and the suppression capability of the air-frequency anti-interference technique for narrowband and wideband interference under the two algorithms is simulated and analyzed,and it is proved that the SMI algorithm has better anti-interference performance than the LMS algorithm,and the influence of different frequency points on the anti-interference performance is also explored.