Research On Millimeter Wave Radar Simulation And Its IF Digital Receiver Implementation Based On FPGA

In this thesis, as the background to the millimeter-wave radar, target echosimulation, as well as IF digital receiver is researched. Two radar echomodel,LFM-Chirp signal and LFM-SF signal is studyed, and one dimension rangeprofile of LFM-SF has range walk and diffusion phenomena by analysis of these twosignal processing methods,and then verificate the echo waveform and spectrumusing analog signal source. Millimeter-wave radar-based digital IF receiver theory,polyphase filtering method to solve the large amount of computation by the traditionof millimeter-wave radar receiver technology, the I/Q channel quadrature poorperformance.The main subject of the work is summarized as follows:(1) For millimeter-wave echo model,LFM-Chirp and LFM-SF echo model isanalyzed,and system waveform parameters are designed. Analyzed one dimensionrange profile of LFM-SF due to frequency modulation factor and step frequencyfactor,it has range walk and diffusion phenomena. Finally, the movement to theimpact of one dimension range profile of the two signal is verificated by simulation.(2) Under the conditions of the original analog signal source, the expansion ofthe radar system, these two different systems signals for LFM-Chirp and LFM-SF isverificated.(3) Conventional quadrature receiver technology has a large amount ofcomputation and I/Q channel quadrature poor performance issues, PolyphaseFiltering IF digital channel is designed by application of digital quadrature receivertheory. Obtained through the analysis of multi-phase filtering method, the samplingrate is reduced to half its original signal after the parity extract symbols transform, adifference of half a cycle of I/Q signal in the time domain, obtained from thesimulation based on polyphase filtering method the good performance of digitalorthogonal orthogonal.(4) Design algorithm based on dual-channel processing FPGA digital quadratureprocess, and then designed IF digital receiver module for I/Q channel time for theparity extract symbolic transformations on the dislocation so that I/Q two questionsthat are not orthogonal,design a state machine to make the two consistent, andwholepass filter to achieve the purpose of orthogonal two sig nals, and finallysuppress interference in the system by low-pass filter module.