Waveform design and imaging method of MIMO ISAR based on orthogonal LFM signal

摘要

Orthogonal frequency division multiplexing linear frequency modulation (OFDM-LFM) is widely applied in multiple-input multiple-output (MIMO) radar systems to obtain better orthogonality and range resolution. However, when it is used in MIMO inverse synthetic aperture radar (ISAR) imaging, the frequency interval between each sub-signal will cause different Doppler effects in the target scattering centre echo. Azimuth deviation will occur after azimuth imaging. To eliminate the deviation, orthogonal LFM with different chirp rates are adopted and designed in this paper. The frequency interval is avoided, and the better performance of ISAR images is ensured. With the flow of MIMO ISAR imaging based on orthogonal LFM, simulations and comparisons are conducted to verify the validity of the designed waveform and imaging method.