Research On Anti-jamming Technology Of GPS Array Antenna And Realization Of Hardware Platform

The global satellite navigation system with its high precision,all-weather and global coverage of the advantages,whether in civilian areas or in the military field,is in a pivotal position.But at the same time,the distance between the satellite navigation signal and the receiver equipment is very far away,and the power of satellite navigation signal itself is low,this causes the receiver to be easily disturbed by various kinds of interference signal,which is represented by the most common suppressed jamming signal.Finally the receiver can not achieve the correct function of navigation and positioning.Therefore,in order to make the receiver can still work normally under the interference of interference signal,there is a lot of anti interference technology.Firstly,the thesis analysed the structure of the GPS signal and the characteristic of the jamming signal.It is concluded that the suppression jamming signal is the main type of interference to the receiver equipment.Then the signal received by several common antenna array is modeled.This thesis introduces the several equivalent of wave filtering optimization principles.The formation principle of the pattern of antenna array is illustrated.Two classical adaptive filtering algorithms are presented.Consideration of the actual working conditions of the integrated receiver equipment,and through the comparison and analysis of the preconditions of the use of various adaptive anti jamming algorithms,it is put forward that the power inversion adaptive anti jamming algorithm can be carried out for the large power jamming signal under the condition of no need to know the direction of the desired signal and the interference signal.In the process of the research of the algorithm,by combining the least mean square error algorithm,the algorithm is reduced,and the performance of the algorithm is studied by Matlab simulation.Several factors that affect the performance of the algorithm are studied and analyzed.It is proved that the power inversion adaptive anti jamming algorithm can suppress the jamming signal effectively without knowing the direction of the desired signal.Finally,based on the FPGA,the Adaptive Anti-jamming module of the array antenna is studied,and the overall design scheme and work flow of the module are analyzed and determined.By using the hardware description language,the design of the top layer module and each sub module are completed.And the RTL level circuit diagram of each module is completed.Such as the digital control oscillator,mixer,FIR low pass filter,anti-jamming algorithm module and digital up conversion and other parts of the work are realized.Thesimulation of the design is simulated by using Modelsim.When the weight of the power inversion adaptive anti interference algorithm achieves convergence,the weight of each array element is read.And the results are compared with the weights obtained by Matlab simulation.The correctness of each convergence weight data in FPGA is verified.Then use the two sets of weights to use Matlab to form the antenna array pattern,intuitive comparison,the experimental results verify the effectiveness of the design of the module.