Research On Digital Multibeam Synthetic Technology For Interplanetary Scintillation(IPS) Telescope

By studying the interplanetary scintillation,the angular structure of the dense source can be studied,and the solar wind velocity and solar wind plasma irregular structure can be measured.In this paper,the key technology of ming'an-tutu interplanetary scintillation telescope,digital multibeam synthesis,is studied.By using this technology,multiple beams can be formed and multiple radio sources in the sky can be observed at the same time.1)this paper introduces the principle of conventional beamforming algorithm and adaptive beamforming algorithm in the way of block diagram,and focuses on the MVDR algorithm,LCMV algorithm,MSINR algorithm and MMSE algorithm,which are four commonly used adaptive beamforming algorithms.Then,the different digital beamforming algorithms are simulated based on MATLAB.The first case,different array apertures are set,and the relationship between beam width and array aperture is verified by comparing and analyzing the returned beam width.The second case,by setting the same array conditions,the performances of five digital beam algorithms,including conventional beam algorithm,minimum variance distortionless(MVDR),linear constrained minimum variance(LCMV),maximum signal to interference ratio(MSINR)and minimum mean square error(MMSE),are compared,none of which can meet the technical requirements of the sidelobe of the interplanetary scintillation telescope.2)Since the present digital beamforming algorithm cannot match the requirements of the interplanetary scintillation telescope,the existing digital beamforming algorithm is improved,and a beamforming algorithm suitable for the ming'an-tu interplanetary scintillation telescope is proposed.Through simulation,the algorithm can meet the needs of the interplanetary scintillation telescope.Due to the large number of channels in the array and the high complexity of the algorithm,a sub-array optimization method is proposed,which greatly reduces the complexity of the algorithm,and also reduces the resource consumption in hardware implementation.based on a single beam,an algorithmof multibeam synthesis is also proposed,and the algorithm is simulated to form four main beams.3)The conventional beamforming algorithm for hardware implementation of the early work,the weight of beamforming is calculated in advance in Matlab,deposited in ROM.Using Verilog HDL language,the hardware implementation scheme is designed,And write the test code,conduct the function simulation(behavior simulation)to the design input,verify the correctness of the design function.