9 / 2019-11-24 01:08:00

A low-complexity beamspace-based algorithm for two-dimensional DOA estimation in massive MIMO systems

Massive multiple-input multiple-output; DOA estimation; beamspace; propagator method

The complexity of the DOA estimation algorithm for massive multiple-input multiple-output (MIMO) systems is critical and extremely affects its application. To reduce the computational complexity, we propose a new low-complexity DOA
estimation algorithm based on the beamspace transformation and the improvements of propagator method (LBPM). Specifically, the received signal vectors in the antenna-element space are transformed into the beamspace by employing beamforming vectors, which simplifies the array manifold so that the total dimensions
of the received signal vectors are significantly reduced. Then, the transformed data is conjugated and rearranged to improve the precision of the proposed algorithm. Finally, the LBPM which with the least squares process and without any eigenvalue decomposition of the covariance matrix are employed to further
reduce computational complexity. Numerical simulations indicate that the proposed algorithm enjoys better DOA estimation performance than that of the conventional estimators in massive MIMO systems.