High-resolution direction finding for MIMO radar systems without eigendecomposition

By simultaneously transmitting and receiving multiple coded waveforms with multiple-input multiple-output (MIMO) configuration, the MIMO radar appears more attractive than the traditional phased array radar in performance. However, when applied in the MIMO radar system, the classical subspace-based methods for high-resolution DOA estimation are computationally prohibited as the observed covariance matrix is the Kronecker product of the transmit and receive covariance matrices, considerably increasing the size of the covariance matrix. To cure this problem, a computationally efficient subspace-based method for DOA estimation is addressed in this paper. The proposed method only needs vector-vector operations, and does not involve the covariance matrix calculation and its EVD or inversion operations. Therefore, the proposed method is computationally attractive for practical applications. Numerical results are included to illustrate the performance of the proposed method.