Research And Implementation Of Receiving System For Miniature MIMO High Frequency Surface Wave Radar

High Frequency Surface Wave Radar(HFSWR)is a new radar system with low cost,easy maintenance,beyond-line-of-sight and all-weather characteristics.However,due to the low operating frequency of the radar,in order to meet the requirements of the radar system,the aperture of the receiving antenna array is large,which can reach the kilometer level.This characteristic greatly limits the development of HFSWR.The combination of Multiple Input Multiple Output(MIMO)technology and radar systems can realize the virtual aperture of the receiver array,increase the effective aperture of the receiver array,improve the angular resolution of the target,reduce the transmitting power and realize the miniaturization of the radar antenna array.Therefore,the research of MIMO HFSWR is very important.In view of the actual requirements of MIMO HFSWR,this paper aims at the research and implementation of the receiving system.The receiving system can complete the AD sampling of echo signals and digital signal processing based on CUDA(Compute Unified Device Architecture)programming,and finally draw the RD spectrum to display the target information.The relevant research carried out in this paper is as follows:First,this paper introduces the signal generation of miniature MIMO HFSWR.Firstly this paper introduces the slow time MIMO signal model used in the miniature MIMO HFSWR system and the working principle of the excitation signal card.Then,this paper debuts the excitation signal card,and verifies the transmitting waveform obtained.Second,this paper introduces the signal processing of miniature MIMO HFSWR.Firstly,the digital down conversion module and baseband signal processing module in the signal processing of MIMO HFSWR are analyzed theoretically.The multi-rate signal processing theory is introduced in the digital down-conversion module,and the antialiasing filter is analyzed.In this paper,the polyphase filter is used as the anti-aliasing filter,and the parameters of the filter are set up and verified by simulation.The principle of solving the distance information and velocity information is introduced in the baseband signal processing module.Then,combined with the signal processing theory,the simulation of the whole system is completed to verify the feasibility of the system.Third,this paper introduces the the hardware implementation of the receiving system.Firstly,the working principle of the acquisition card is introduced,and the acquisition card is debugged.Then,in the signal processing of digital signal after AD sampling,this paper chooses to use GPU accelerated operation card for parallel processing,which is realized based on CUDA programming.The hardware architecture of GPU and CUDA programming model are introduced,and the digital signal processing algorithm based on CUDA programming is briefly described.The signal processing algorithm based on CUDA programming is proved to be correct and efficient by comparing with the signal processing on Matlab.Fourth,this paper introduces the experimental verification of miniature MIMO HFSWR.Firstly,the laboratory experiment is carried out to verify the system.Then,based on the experimental environment of Weihai radar station,a field experiment is carried out and the effectiveness and feasibility of the system are analyzed according to the measured data.