Low complexity root-MUSIC algorithm for angle estimation in monostatic MIMO radar

A low complexity direction of arrival (DOA) estimation method based on the real-valued root-multiple signal classification (MUSIC) algorithm is proposed for DOA estimation in monostatic multiple input multiple output (MIMO) radar. Firstly, the dimension of the received data is reduced by the reduced-dimensional transformation and the real-valued covariance matrix of the received data is obtained by unitary transformation. Then a unitary MUSIC-based polynomial is constructed in the low-dimensional space to estimate the DOA of targets. To further reduce the computational complexity, the complex polynomial is mapped into a real-valued one by conformal mapping, and finally the DOAs can be obtained by finding the roots of the real polynomial. The method requires no peak searching and the eigenvalue decomposition and polynomial rooting are all carried out in the real domain, and it can obtain improved angle estimation performance with greatly reduced computational complexity. Simulation results verify the effectiveness of the proposed algorithm.