Maximum likelihood estimation of DOD and DOA for bistatic MIMO radar

In this paper, the maximum likelihood estimation (MLE) of the direction of departure (DOD) and direction of arrival (DOA) of multiple targets for bistatic multiple input multiple output (MIMO) radar is addressed. We derive the maximum likelihood estimator of the DOD and DOA with the assumption that the targets are unknown but deterministic. Moreover, we provide a compact expression of the Cramer Rao bound (CRB) under this nonrandom framework. Since the MLE of the target DOD and DOA is related to a high-dimensional nonlinear optimization problem, we propose alternating projection (AP) to solve it efficiently. Numerical simulations demonstrate that the AP based MLE can provide accurate estimations of the target DOD and DOA and achieves the CRB in the asymptotic region. Furthermore, results also show that the proposed algorithm outperforms the existing ESPRIT and MUSIC algorithm for the uniform linear array (ULA) configuration of the transmitted and received array. ► The maximum likelihood estimator of the target DOD and DOA for bistatic MIMO radar is derived under the unknown but deterministic framework. ► A compact expression of the CRB for angle estimation of the bistatic MIMO radar is given. ► Alternate projection is utilized to solve the MLE problem efficiently. ► An adapted space searching method is proposed to accelerate the AP algorithm and improve the estimation accuracy.