Joint Suppression of Range-Ambiguous Clutter and Mainlobe Deceptive Jammer via 3-D RANM-STAP With PFDA-MIMO Radar

In radar systems, range-ambiguous clutter and mainlobe deceptive jammers severely impair the capability of moving target detection (MTD). To address this issue, a joint suppression scheme via three-dimensional reweighted atomic norm minimization space-time adaptive processing (3-D RANM-STAP) with planar frequency diverse array multiple-input multiple-output (PFDA-MIMO) radar is developed. In the PFDA-MIMO system, frequency increments are introduced along both the row and column dimensions of the planar array, enabling two-dimensional (2-D) range degrees of freedom (DOFs). To separate the target from echoes contaminated by jammers and clutter, a 2-D range-dependent compensation (RDC) technique is employed. Furthermore, design criteria for the frequency increments are derived to enhance the separation performance. Utilizing the range DOFs in the elevation transmit dimension, an adaptive pre-STAP filter is designed to suppress both cross-pulse repeater jammers (deceptive jammers delayed by more than one pulse relative to the true target) and range-ambiguous clutter. Subsequently, the 3-D RANM-STAP is performed to jointly suppress intra-pulse repetition interval (PRI) rapid repeater jammers (deceptive jammers sharing the same number of delayed pulses as the true target) and local clutter. Herein, the clutter-plus-jammer covariance matrix (CJCM) is estimated by solving a 3-D RANM problem with a nonconvex sparse metric, thereby offering enhanced sparsity and resolution. Numerical simulations demonstrate the effectiveness of the proposed scheme, with a performance loss within 3dB of the theoretical optimum.