Robust waveform design for MIMO–OFDM‐based STAP in the presence of target uncertainty

Abstract

The issue of robust orthogonal frequency division multiplexing (OFDM) multiple-input multiple-output (MIMO) radar waveform design is investigated here with target uncertainty to enhance the worst-case space-time adaptive processing (STAP) detection performance of MIMO–OFDM radar. Based on the max–min method, the robust waveform optimisation problem is constructed under the criterion of maximising the worst-case output SINR, namely, signal–interference–noise ratio, with constraints of constant modulus and target estimation errors to enhance the robustness of STAP's detection performance to target uncertainty. To handle the obtained non-linear and complicated issue, an approach based on diagonal loading (DL) is presented. By employing DL method, the optimisation issue can be relaxed to semidefinite programming one, and thus it can be tackled very efficiently. When compared with uncorrelated signals, the state-of-the-art robust and non-robust waveform design methods for MIMO–STAP, numerical simulations reveal that the developed approach can enhance the robustness of the detection performance of STAP significantly.