MIMO SAR Chirp Modulation Diversity Waveform Design

Waveform diversity design is a vital issue in multiple-input multiple-output (MIMO) synthetic aperture radar (SAR) systems because the waveforms should have good orthogonality, high coherence, and large time-bandwidth product. However, most of the existing waveforms are not suitable for MIMO SAR and difficult to be implemented in a real-life scene. This letter investigates a scheme for designing chirp modulation diversity waveforms with large time-bandwidth product, constant modulus, implementation simplicity, good Doppler tolerance, and orthogonality. The four waveforms are orthogonal on both transmit and receive. The waveform performances are investigated through the correlation and ambiguity functions. Numerical results validate the superiorities of the designed four waveforms in MIMO SAR high-resolution imaging.