Performance analysis of a null-steering algorithm based on direction-of-arrival estimation

A two-step null-steering algorithm is considered. The first step consists of estimating the directions of arrival of all wavefronts impinging on a sensor array. The second step consists of forming nulls in the estimated directions of the interferers, while maximizing the received signals. A first-order performance analysis is carried out, leading to an asymptotic formula for the output interference-to-signal ratio (OISR). Numerical examples are presented to illustrate the dependence of the OISR on the spatial separation of the interferer and the signal and on the array aperture.<>