Search-free DOA Estimation Method Based on Tensor Decomposition and Polynomial Rooting for Transmit Beamspace MIMO Radar

In order to improve the accuracy and resolution for transmit beamspace multiple-input multiple-output (MIMO) radar, a search-free direction-of-arrival (DOA) estimation method based on tensor decomposition and polynomial rooting is proposed. In the proposed method, a 3-order tensor is firstly designed to model the received signal of MIMO radar on the basis of the multi-linear property. Then, the factor matrix with target DOA information is obtained by the tensor decomposition via alternating least squares (ALS) algorithm, and subsequently the DOA estimation is converted into independent minimization problem. In the following, a polynomial function is constructed by exploiting the Vandermonde structure of the transmit steering vector of MIMO radar. The factor matrix contained in the polynomial can be regarded as a block matrix in the generalized sidelobe canceller (GSC), which accordingly forms a unique deep null in the direction of target in the transmit beampattern. The proposed method can obtain the DOA estimation without the requirements of spectrum searching or transmit beamspace matrix design, which is different from the conventional DOA estimation techniques. The effectiveness and performance of proposed method is verified by the simulations.Comment: 5 pages, 4 figures, submitted IEEE Antennas and Wireless Propagation Letter