DOA Estimation of Quasi-Stationary Signals with a Nested Array in Unknown Noise Field

The problem of direction-of-arrival (DOA) estimation of quasi-stationary signals using a nested array in unknown noise field is investigated and two methods based on differencing method and eigenspace are proposed in this paper. Through performing differencing between the virtual received data, the unknown noise component is directly removed from the data model. The resulting data model is then utilized to find out the DOAs of the signals based on the theory of subspace. Thanks to the configuration of the nested array, it can produce large degrees of freedom (DOF) in the virtual sensor array which provides the virtual received data. These increased DOF can contribute enhanced resolution in DOA estimation. Numerical simulations of DOA estimation exhibit the effectiveness and superiority of the proposed methods.