Doppler ambiguity resolution based on random sparse probing pulses

A novel method for solving Doppler ambiguous problem based on compressed sensing (CS) theory is proposed in this paper. According to the Restricted Isometry Property (RIP) of the CS sensing matrix, a sparse pulse train are randomly extracted from traditional fixed repetition frequency pulses, and then a random perturbation item is added to the transmitting time of each selected pulse. The received signals after matched filtering can be viewed as randomly sparse sampling from the traditional fixed-PRF (pulse repetition frequency) echo signals. With the transmitting time sequence, a sensing matrix can be built and the whole target echo could be recovered via CS recovery algorithms. Through refining the sensing matrix, which is equivalent to increase the sampling frequency of target characteristic, the Doppler unambiguous range is enlarged. Compared with traditional methods, the proposed method only requires transmitting a few sparse probing pulses to achieve a larger Doppler frequency unambiguous range and can reduce the consumption of the radar time resources. The radar dwell scheduling only needs slight adjustment, thus our proposed method has great value of practical application.