OFF-GRID DIRECTION-OF-ARRIVAL ESTIMATION USING A SPARSE ARRAY COVARIANCE MATRIX
Xiaoyu Luo, Xiao Chao Fei, Lu Gan, Ping Wei · Progress In Electromagnetics Research Letters · 2015
An off-grid direction-of-arrival (DOA) estimation method that utilizes a sparse array covariance matrix is proposed. In this method, the array covariance matrix is sparsely represented in the form of a vector and then modified to become an off-grid DOA estimation model according to the first-order Taylor series. By solving for the two sparse vectors in the resulting array covariance matrix, the off-grid DOA estimation can thus be achieved. We present an alternating iterative algorithm that exploits the alternating update of a convex optimization problem and a least-squares problem to solve for these two sparse vectors. Our method also extends the aperture. The effectiveness and efficiency of the proposed method are demonstrated in the simulation results.