| With the intensive use of the satellite navigation system Beidou in the civilian and military,it will face more and more problems.Because Beidou’s navigation satellite signal is very weak,it is easy for multiple type of interference.To guarantee the stability and reliability of the Beidou satellite navigation operation,the research for the Beidou adaptive interference prevention technology is imminent,it is of significant significance to use an effective adaptive anti-jamming method to improve the robustness of the Beidou satellite navigation system.1)This paper describes the power inversion(PI)algorithm under the linear constraint minimum variance(LCMV)criterion in detail,and simulate the impact of the number of snapshots,the number of array elements,and interference to signal ratio on the anti-jamming performance using MATLAB.This paper studied the sampling matrix inversion algorithm,least mean square algorithm and recursive least squares algorithm,decided to use the sampling matrix inversion algorithm as the weight solving method,and then introduced the matrix inversion method based on Cholesky decomposition to greatly reduce the algorithm hardware implementation difficulty.2)This paper proposes the design and implementation of a seven-element anti-jamming baseband system based on FPGA hardware platform.Firstly,a hardware design for the system was proposed,including FPGA introduction and selection,ADC circuit,clock circuit and DAC circuit.After that,an FPGA based anti-jamming algorithm implementation architecture was introduced,especially the high-speed serial data acquisition module,data preprocessing module,weight calculation module and baseband signal floating-point weighting and output module.In the process of designing the above modules,to guarantee the precision of the weight of the anti-jamming algorithm while reducing resource consumption,this paper adopts a data processing method combining fixed-point number and floating-point number.In addition,this paper puts introduce the method of encapsulating the adaptive anti-jamming processing algorithm into the IP core by using the tool of high level synthesis(HLS),which shortens the development cycle of the entire project.3)This paper first verifies the design of seven-element anti-jamming baseband system,and comparison of MATLAB simulation anti-jamming performance and baseband processing board anti-jamming performance,and the reasons for the differences in their anti-jamming performance have been analyzed.After that,a field test platform is established to examine the anti-jamming performance of the seven-element anti-jamming baseband system that is designed.Through the field test results of anti-jamming performance,the designed seven-element anti-jamming baseband system met the expected design objectives. |
