Adaptive beamforming passive radar based on FM radio transmitter

One of the major problems in continuous wave bistatic radar based on FM radio transmitter is direct path interference(DPI). This is the signal received directly from a transmitter by the receive channel antenna. The DPI and the reflected signal are coherent, have similar structure except for the mutual delay and Doppler frequency shift. To detect targets it is necessary to suppress or remove the DPI signal. First of all, the DPI signal based on FM radio transmitter is analyzed. Secondly, the approach based on adaptive nulling array processing is introduced in detail to solve this problem. Finally, associated signal processing schemes of the FM-radio-based passive radar is discussed. Simulation results by applying real collected data show the proposed method is effective.