FFT-based adaptive 2-D DOA estimation for arbitrary array structures

Abstract

Direction-of-arrival (DOA) estimation is a ubiquitous task in array processing. The conventional MUltiple SIgnal Classification (MUSIC) method is search-based and often computationally expensive, particularly in the application of joint azimuth and elevation estimation. In this paper, we propose an adaptive 2-dimensional direction finding framework to track multiple moving targets for arbitrary array structures by using the manifold separation technique (MST). First, we employ the subspace tracking technique to update the eigenbasis recursively on the arrival of a new data snapshot. In addition, by using the shift matrix a fast one-step operation is found to update the coefficient matrix in parallel. Finally, 2-D fast Fourier transform (FFT) algorithm is performed to compute the 2-D spatial spectrum at once. In comparison with the traditional MUSIC or root-MUSIC methods, the proposed method can reduce the computational complexity considerably.