| Bistatic/Multistatic MIMO radar, as a new radar system, combines the advantages of bistatic/multistatic radar and MIMO radar, which can improve the accuracy of target location and performance of weak target detection and has the capability of RF stealth. These advantages make bistatic/multistatic MIMO radar be worth researching.The characteristics of clutter and clutter’s impact on target detection and tracking of Bistatic/Multistatic MIMO radar system are different from monostatic radar, and the characteristics of bistatic/multistatic radar makes time and frequency synchronization have become an important issue. In this thesis, the basic principle and signal processing of Bistatic/Multistatic MIMO radar were introduced, and clutter modeling,clutter suppression, slow and low level target detection and target tracking under clutter and time-frequency synchronization problems were discussed. The main contents include the following:1, Introduced the basic principles and characteristics of the bistatic MIMO radar, and using LFM signal as the signal of bistatic MIMO radar, the main process is discussed including signal transmitting, signal receiving, matched filtering, beam forming, moving target detection and information fusion.2, Utilized a suitable model for the clutter of bistatic/multistatic MIMO radar and verified the accuracy of model by simulation; analyzed the impact of the windowing, long time integration and Clean on clutter suppression and verified the effectiveness of these three methods.3, Simulated slow and low-altitude target detection under the clutter, and the simulation results showed that the OS-CFAR is more suitable for bistatic/multistatic MIMO radar detection than the CA-CFAR; verified the windowing and time accumulation for the inhibition of clutter, which in turn improves the detection performance; target detection performance is analyzed under different conditions, and The results indicated that the target which has a greater speed, a longer distance from the radar system transmitting to receiving stations and the higher heights would be more easily detected.4, Researched the impact of clutter on the target tracking. Introduced the basic model of target motion and tracking filtering algorithm, and analyzed the performance of target tracking under the clutter. Used long time integration, windowing and Clean to suppress clutter to improve the tracking performance of bistatic MIMO radar.5, Researched the impact of time and frequency synchronization on the signal processing. Analyzed the demands of time frequency synchronization for the bistatic MIMO radar, and chose the most suitable scheme among the currently existing time and frequency synchronization schemes. Introduced the basic principles and methods of GPS synchronization. Derived the impact of system timing error on the CRLB of time delay estimation of bistatic MIMO radar and then analyzed the impact of the timing error on radar range. Derived the impact of the frequency stability on the CRLB of Doppler frequency estimation in the two different situations which is that frequency is stable and frequency is not stable in the process of long time integrated. |
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