Direct-path signal obtaining to digital video broadcasting transmitter radar based on the spatial filtering

The direct-path signal obtaining is important to system performance in passive radar based on digital video broadcasting illuminator. It was proposed that direction of arrival wave (DOA) is estimated, then spatial filtering is performed, to suppress interference brought by the multiple-transmitter. For DOA estimation, the forward or forward-backward spatial smoothing techniques were adopted to solve coherent signals. For spatial filtering, the ordinary broad null algorithm was extended into forming multiple broad nulls and flexible beam pointing according to the character of the passive radar. In addition, the complexity of the arithmetic can be simplified for real-time realization as the uniform linear array is used. The simulated results show that the algorithm can better suppress interference brought by the multiple-transmitter.