Research On Anti-jamming Technology Of Beidou Navigation Based On Adaptive Filtering

The satellite navigation is a necessary in the production and daily life.But the navigation signal is easily jammed because of its weakness and the increasingly complex electromagnetic environment,resulting in false position or even losing its navigation function.So the anti-jamming technique has become more and more important.This thesis mainly does research on interference suppression based on adaptive filtering for Beidou Navigation Satellite System.The main content are as follows:1.The spatial adaptive processing(SAP)algorithm based on LCMV is researched with a 7-element antenna array.The performance of the spatial algorithm is investigated with the power inversion blind adaptive algorithm and the MVDR algorithm.2.The space-time adaptive processing(STAP)is studied to break the limit of element number.The effects of jamming signal number and delay cell number are investigated.The performance of STAP is compared with that of SAP.And the simulation results prove that STAP increases the DOF(degrees of freedom)of adaptive weights but also increases the amount of calculation.3.The space-frequency adaptive processing(SFAP)is studied as an advanced structure of STAP in the frequency-domain.The effect of jamming number and frequency subbands number on the output performances of SFAP is also presented.The simulation results show better wideband performance and lower complexity of SFAP than those of STAP.Then the equivalent conditions are derived on which SFAP has the same output with STAP.4.An advanced algorithm based on space-time-frequency domain is proposed.In this algorithm,weight DOF and anti-jamming allowance are obviously increased.And the simulation results prove its good performance with multiple interference signals.5.The hardware model of SFAP is described on the FPGA chip.The hardware system is debugged in the assistance of MATLAB results and the algorithm performance is verified during the experiment.