Design And Implementation Of Signal Processing System For Radio Spectrometer Based On Casper And Simulink

Extreme space weather phenomena caused by solar outbursts can have adverse effects on human activities such as short-wave communications,power systems,and satellite navigation.Solar radiation covers a very wide frequency band from radio waves to ultraviolet light.The solar radio telescope is a large electronic device that monitors solar activity.The data processing system of the radio telescope is mainly realized by FPGA.However,the logic coding,simulation and debugging of FPGA are difficult and time-consuming.This is why the Casper Universal Hardware Platform can be born and promoted worldwide.Casper is a general-purpose hardware development platform for radio astronomy digital terminals.The bottom layer is reconfigurable open source hardware based on Xilinx FPGAs.Based on the Casper hardware development platform,the Casper library provides software packages for the processing of radio astronomical signals.The system generator tool can be used to develop FPGA signal processing functions in the Simulink graphical environment,which greatly improves the development efficiency of radio astronomy equipment.A receiving unit of the solar radio telescope can be used as a solar radio spectrum analyzer.This paper designs a signal processing system for the solar radio spectrum analyzer based on the ZYNQ7000.Firstly,Using Casper module and Simulink Xilinx module in Simulink design signal processing module.Then it is converted into FPGA engineering by System Generator tool.We write the simple logic control and other necessary modules by verilog,and build the hardware processing system of the telescope unit prototype in the Vivado development environment.The system mainly completes the analysis of solar radio signals in time and frequency domain.In order to realize the real-time remote monitoring of solar radio spectrum analyzer,the terminal real-time visual receiving software is also designed.The main research work completed in this paper is summarized as follows:(1)Research on the development status of digital radio telescopes and solar radio spectrum analyzers at home and abroad.(2)In-depth understanding of the solar radio spectrum analyzer system;learn to use the Casper module and Simulink Xilinx module in conjunction with Vivado to design the digital signal function;understand the working mode of remote transmission.(3)The signal processing system of the unit prototype is jointly designed by the Casper module and the Simulink Xilinx module,which mainly performs functions such as orthogonal digital down conversion(DDC)and spectrum analysis and so on.The system generator tool is then used to export the designed function module to the IP core that can be invoked in the Vivado project.Use Verilog programming to implement integral accumulation module,FPGA and ARM communication module to prepare for data serial output.(4)The remote transmission terminal receiving software is designed through VS MFC development environment.Which is mainly realizes real-time visual display and reception of spectrum information.The input data is drawn in MATLAB and compared with the graphics received by the software to verify the correctness of the software design.(5)Based on the ZYNQ7000 development board,a hardware system is built in the Vivado project to carry out the operation of the signal processing system and the spectrum information remote transmission process.The spectrum analysis results of the serial port output are compared with the results of the spectrum analyzer in MATLAB to verify the correctness of spectrum analysis module and the serial port output module.The output of the quadrature digital down conversion is connected to the spectrum analysis module,and the correctness of the DDC is verified according to the output spectrum.Finally,the resource usage of the system is analyzed.