A low-Copmlexity 2D DOA Estimation Algorithm for Massive MIMO Systems

The conventional direction of arrival (DOA) estimation algorithms, e.g., MUSIC, Capon, ESPRIT, may not be effective when applying to massive Multiple-Input Multiple-Output (MIMO) systems because they suffer from forbiddingly high computational complexity. This paper proposes a low-complexity 2D DOA estimation algorithm for massive MIMO systems. We first obtain coarse initial DOA estimates via the discrete Fourier transmission (DFT) and then search for the accurate estimates by reduced-dimensional Capon algorithm within a very small region. Compared with traditional Capon algorithm, the proposed algorithm owns much lower computational complexity because of the coarse initial and the reduction of dimension. Theoretical analysis and simulation results demonstrate that the algorithm outperforms PM and ESPRIT methods. Besides, it is proved to be efficient for Internet of Things (IoT).