MIMO-STAP Based Cognitive Design of Transmitted Waveforms and Receive Filters for Clutter Suppression

This paper considers the problem of the cognitive design of transmitted waveforms and receive filters for an airborne multiple-input multiple-output (MIMO) radar in the presence of clutter. In order to enhance the detection performance, we propose a novel sequential optimization method to maximize the output signal-to-clutter-plus-noise ratio (SCNR). Additionally, the constraint of a constant-envelope as well as the transmit energy constraint is taken into account. We use a semi-definite relaxation method to tackle the NP-hard optimization problem, and a randomization method to synthesize the transmitted waveforms, based on the waveform covariance matrix (WCM). The receive filter design is reformed with the minimum variance distortionless response (MVDR) method. We prove the devised algorithm yields solutions guaranteeing an increase in SCNR at each iteration. Moreover, the SCNR curve associated with the proposed algorithm has narrower clutter notch than that of the coherent waveform and the orthogonal waveform. Finally, we validate the proposed algorithm by several numerical results.