Research On Some Key Problems Of DMB-T Digital TV Based Passive Coherent Radar

Bistatic (Multistatic) Radar System based on external illuminators becomes the focus of researching on radar system because of its advantages. Passive radar using Digital Video Broadcast-Terrestrial signals as external illuminators is the new Research direction of radar technology with the development of digital television technology. Based on using signal of DMB-T which is the standard of terrestrial-digital-multimedia-television-broadcasting made by Tsinghua University as external illuminator, firstly this paper researches on the key technology in DMB-T, which is OFDM. We study OFDM principle and its key problems and solutions, meanwhile explain detailedly the frame structure, system parameters, signal feature and how to use signal feature to estimate channels and synchronize. The research content provides a basis for radar detection via Digital Video Broadcast-Terrestrial signals. And then the structure of radar system using Digital Video Broadcast-Terrestrial signals as external illuminators is designed. We mainly study equalization technique for purifying reference channels and discus algorithms of equalization, clutter canceling and Range Doppler. We simulate the algorithms of equalization including zero-forcing, adaptation and decision-feedback algorithm. And these algorithms are analyzed. Finally the Radar System based on external illuminators is simulated. The simulation results show that clutter canceling would get good effect with equalization technique.