Research On Real-Time Simulation Technology Of Target Echo Response Based On FPGA

With the continuous development of radar technology,performance testing radar systems have become increasingly important.The use of real field tests not only takes up a lot of human and financial resources,but is also vulnerable to extreme weather conditions.The real-time simulation technology of radar target echo simulates the target echo signal and noise signal in the real test environment of the external field,which can well replace the external field experiment,fully reflect the radar echo characteristics,help improve the radar system related design and production defects,provide convenience for research and development,and accelerate the development progress.In this paper,the SAR radar target real-time simulation project is used as the task source,and the modeling development tool System Generator is used as the development platform.The target echo response real-time simulation system based on FPGA is designed and implemented.Combined with the convoluted system,the generated real-time target echo response function is convoluted with the received radar excitation signal to generate the SAR radar real-time target echo signal to help test the radar system performance.The work of this paper is as follows :1.Combined with the project situation,the system requirements analysis is carried out,and the technical framework design of real-time simulation of SAR radar target echo response is carried out,including calculation task division,sub-unit(processor)planning,calculation parallelism,pipeline and superposition strategy design,specified model FPGA chip resource evaluation,etc.2.A reference map expansion method for generating radar reference map data for target echo simulation is provided.Considering the difficulties in obtaining SAR images(generally obtained through flight tests),interference in images,and insufficient data in radar echo simulation,the deep learning framework is applied,and the Cycle GAN model is used to generate the reference map to realize the expansion of SAR target images,which provides a sufficient experimental basis for radar target echo simulation.3.The FPGA modeling,design and implementation of real-time simulation of the target echo response are completed.Based on the System Generator platform,the frame analysis module,various types of data reading and writing modules(reference map,block number,PRF,etc.),ground coordinate expansion module,calculation module,Sinc interpolation module,superposition module and other functional modules included in the target echo real-time simulation system are designed and implemented.The target echo response calculation and real-time simulation are realized by 36 FPGAs with the same design.4.Complete the radar target echo response real-time simulation system test.The three-dimensional simulation of Matlab numerical simulation,System Generator model simulation and FPGA on-board test is carried out.The test results are collected,and the system functions realized by the design are compared and verified.Through the calculation time evaluation and FPGA resource evaluation,it is shown that the designed simulation system meets the performance constraints of the specified chip and the project task requirements.