Study Of GNSS Antenna Phase Center And Anti-jam Technology

GNSS has important application value in the field of military and national economy, while has made a rapid progress during the past 20 years, but the navigation signal is easy to be jammed. Lots of papers have been published on space-time anti-jamming algorithms for GNSS, but most algo rithms aimed at optimization output SINR. However, carrier to noise ratio(C/N0) was determined as evaluating indicator in GNSS, and it is of great significance to study space-time anti-jamming algorithm which leads to maximum C/N0. In addition, the problem of real time and the GNSS antenna phase center variation would also need to be considered.Therefore, on the basis of the basic principle of navigation and positioning, space-time anti-jamming algorithm which leads to maximum C /N0 is studied. Furthermore, the contrast analysis of two kinds of reduced-dimension algorithms is gave from the angle of real- time, and the influence of array elements phase center and the array equivalent phase center is studied. At last, actualized the algorithm on FPGA platform. The specific contents are as follows:First of all, introduced the theoretical basis for using C/N 0 as index in GNSS, then derived the weight expression of the space-time anti-jamming algorithm based on max C/N0 criterion, eventually compared with several traditional space-time anti-jamming algorithms.Secondly, briefly covered the basic principle of lower dimensional adaptive processing, analyzed the reduced-dimension algorithm based on the method to design the time-domain filter. A new Reduced-dimension algorithm based on compressed sensing is proposed, based on the basic theory of compressed sensing. Compared with the reduced- dimension adaptive processing algorithm based on the FIR filter design method, this algorithm has the advantages of simple design and excellent performance in the presence of multiple unknown interference source.Thirdly, discussed the affection of the phase center difference between the antennas on the performance of space-time anti-jamming algorithm. The influence of array arrangement on the annates’ s amplitude-phase character is discussed. The problem of the time delay estimation error caused by the variation of the array equivalent phase center which results from the space-time anti-jamming algorithm is discussed.Finally, realized the algorithm on FPGA platform. The radiation pattern corresponded to the simulation results tal ies with the theoretical results.