Range sidelobe suppression for FD-MIMO sonar imaging with FDCW pulses

A range sidelobe suppression method is proposed for frequency diverse multiple-input multiple-output (FD-MIMO) sonar imaging. Unlike traditional methods which suppress cross-correlation functions (CCFs) between transmitting waveforms as low as possible, we use band overlapped frequency diverse continuous wave (FDCW) pulses to obtain relatively high CCFs. We point out that these relatively high CCFs can fill the band gap between auto-correlation functions (ACFs) between neighboring FDCW pulses, thereby showing an ability of reducing the spectrum leakage. Furthermore, we apply an amplitude weight vector to these FDCW pulses to further reduce the spectrum leakage and hence, produce much low range sidelobes. Via theoretical analyses and numerical simulations, we show that the proposed method can produce a high-resolution range profile as well as a low range sidelobe level.