Slow time random phase-coded waveforms in MIMO OTHR

With multiple-input multiple-output (MIMO) technique, skywave over-the-horizon radar (OTHR) is able to implement transmit adaptive digital beamforming (TADBF) to suppress multipath clutter or interference, which is a key technique in next generation OTHR. Time-staggered linear frequency modulated continuous wave and Doppler offset waveforms have been proposed in MIMO OTHR. However, both of the waveforms are constrained by Doppler ambiguity. To solve the problem, a slow time random phase-coded (STRPC) waveforms set fit for both maritime and aircraft surveillance in MIMO OTHR is proposed. And to detect weak targets submerged by cross- correlation peaks caused by strong clutters or large targets, a hierarchical waveform separation (HWS) is proposed. Simulation results are presented to verify the effectiveness of STRPC waveforms and HWS.