Fast Moving Target Focusing with FDMA Radar

This paper deal with the challenge of focusing on fast-moving targets in a frequency division multiple access (FD-MA) radar system. At the modeling stage, the linear frequency modulation (LFM) waveform is transmitted by introducing a frequency increment (at least equal to the bandwidth) across the transmit array elements. The received signals are subsequently processed by a filter bank to separate the transmitted waveforms, which in turn provides additional degrees of freedom in the range domain. Particularly, a compensation procedure is designed to eliminate the incoherence between echos between different transmit element due to frequency diversity. To this end, as the outputs of different matched filters become coherent in the spatial domain, the keystone transform (KT) operation is employed to correct the range walk caused by the fast movement of the target, making it possible to focus the target in the space-time-range domain. Furthermore, the angle of the target is estimated and further utilized for beamforming, enhancing the range resolution. Numerical results are provided to verify the effectiveness of the proposed method in focusing the fast moving target with a FDMA radar.