An improved algorithm for Doppler ambiguity resolution using multiple pulse repetition frequencies

The design of radar waveforms needs to deal with ambiguity resolution both in range and Doppler. Particularly, the waveforms of Pulse Doppler (PD) radars using low pulse repetition frequency(PRF) waveforms are unambiguous in range but ambiguous in Doppler. To solve the problem, the existing detection algorithms are mostly based on the Chinese Remainder Theorem (CRT), but these algorithms do not have a good anti-error ability and require high computational complexity. In this paper, we propose an improved algorithm based on the Discrete Fourier Transform (DFT) rotation factor and the prior Information such as the estimated frequency and velocity of received signals. By traversing the product of the complex vectors and the DFT rotation factor, we can finally figure out the unambiguous velocity. Compared with the existing algorithms, our algorithm is more effective, realizable and has a lower computational load. Finally, simulation results confirm the validity and superiority of this algorithm.