The FPGA Design And Implementation Of Adaptive Anti-Jamming Algorithm In Navigation System

Global Positioning System (GPS) which is developed as assistant navigation toolinitially has been widely employed in civilian and military fields. However, it also drawpeople’s attention because of its defects that are susceptible to interference exposed inthe military action. To bring the advantages of the precision guided weapons into play, itmust rely on the integrity and anti-jamming capability of the GPS system. To improveanti-interference ability of GPS system based on the GPS satellite constellation system,it can cause the formidable cost of hardware. Based on the GPS receiver, we canimprove anti-interference ability via the design of software anti-jamming. Due to theadvantages of easy maintenance and low cost, the anti-jamming technology of softwarewill be applied in more fields.This dissertation presents the implementation of the adaptive anti-jammingalgorithm on a chip of Altera EP3C120F484, which is housed on the GPS receivinghardware board.First of all, this article introduces the basic theories of the adaptive filterrespectively based on pure space and space-time two-dimensional methods. Through thesimulation analysis, we can find that space-time two-dimensional algorithm has obviousadvantages relative to pure space algorithm. And then considering the spectrumcharacteristic of receiving data from Analog-to-Digital converter and the processing ofdigital intermediate frequency signal, an overall framework of adaptive anti-jammingsystem is started. Furthermore, aiming at each module of the whole one, thisdissertation perticularly shows the detail design for algorithm, matlab floatingsimulations and FPGA fixed floating-point simulations of every module.And the core part of the GPS receiver anti-jamming system is the design ofadaptive anti-jamming algorithm. Considering the depletion of hardware resource, LMSfinally is chosen as adaptive tracking algorithm. Due to the limitation of the LMSalgorithm, DLMS algorithm is utilized. And DLMS algorithm is applied into theimplementation of adaptive filter of pure space structure and the space-time twodimensional signal. At last, GPS adaptive anti-jamming algorithm is integrated into the GPS receiversystem. And a further analysis of the validity and the performance of the system is madebased on the practical test results...