Robust prior-based Direction of Arrival estimation

In certain Direction of Arrival (DOA) scenarios some of the sources are approximately known a priori. It is then desirable to be able to exploit this prior knowledge when estimating the DOAs of the unknown sources. In this paper we modify an estimator utilizing exact angular prior knowledge of some sources such that the estimator is able to exploit prior knowledge with some uncertainty. We derive the corresponding Cramér-Rao lower bound and present numerical results showing that the estimator can benefit from prior information, even when it is inaccurate.