An adaptive coding-angle-Doppler clutter suppression approach with extended azimuth phase coding array

摘要

The range ambiguity degrades the clutter suppression performance and incurs parameters estimation ambiguities in application of ground moving target indication (GMTI). Thus, in this paper, an adaptive clutter suppression approach based on extended azimuth phase coding (EAPC) for multiple-input multiple-output (MIMO) radar system is presented. The EAPC array encode the transmit pulses for each transmit element, which can introduce additional controllable degrees-of-freedom (DOFs) in coding dimension at the transmit elements. Then, with the DOFs in transmit, receive and pulse dimensions, the coding-angle-Doppler processing can be performed. The echoes from different range-ambiguous regions can be well separated in joint transmit-receive spatial frequency domain by properly designing the EAPC shift factor. In the sequel, the three-dimensional localization (3DL) technique is employed to suppress the range ambiguous clutters, which can evidently reduce the dimensions of the processor. Finally, the results of the experiments based on simulated data demonstrate that the proposed framework can effectively alleviate the space-time adaptive processing (STAP) performance degradation resulting from the range ambiguity.