MIMO Space-Time Adaptive Processing with Uncertainty in the Knowledge of Target Parameters

Abstract

In this article, colocated multiple-input multiple-output tracking radar is studied; such radar needs robust space-time adaptive processing against target azimuth angle and Doppler frequency mismatches at the beginning of the tracking procedure, and sometime after the tracking begins, higher spatial resolution is required to track the target accurately. First, the target, noise, jammers and clutter signals considering internal clutter motion and covariance matrices are modeled. Then, by imposing two quadratic constraints, such that the STAP response exceeds unity, on a squared surface, and also using Karush-Kuhn-Tucker conditions, the closed-form solution for robust STAP is derived. To suppress the signal cancellation effect, the iterative diagonally loaded method is employed. Simulation results are presented to demonstrate the signal to interference pulse noise ratio performance of the proposed robust MIMO STAP. The results show that MIMO radar has better spatial resolution as well as better signal to interference pulse noise ratio performance in low-velocity target detection. KeywordsClutter covariance matrix; Karush-Kuhn-Tucker (KKT) conditions; Multiple-input multiple-output (MIMO) radar; Robust optimization; Space-time adaptive processing (STAP)