Moving target detection using distributed MIMO radar in non-homogeneous clutter: A subspace approach

Motivated by the fact that the multi-static transmit-receive configuration in a distributed multiple-input multiple-output (MIMO) radar causes non-stationary clutter, we consider the problem of moving target detection (MTD) using a distributed MIMO radar in non-homogeneous clutter environments. A new non-homogeneous clutter model, where the clutter resides in a low-rank subspace with different subspace coefficients for different transmit-receive pairs, is introduced. The subspace clutter model is effective in capturing the non-homogeneity of the clutter and, in particular, the power variations across different aspect angles and resolution cells. A generalized likelihood ratio test (GLRT), which performs local matched subspace detection, noncoherent combining using local decision variables of all transmit-receive pairs and target velocity matching, is proposed. The GLRT is shown to be a constant false alarm rate (CFAR) detector. Computer simulations are provided to verify our statistical analysis of the GLRT, and a comparison with existing detectors is conducted to evaluate the impact of model mismatch on detection performance.