Efficient DOA estimation method employing refined improved polynomial rooting

Finding the direction of arrival (DOA) of several target signals is the most sought after problem in high resolution array signal processing. In this paper, a refined improved polynomial rooting (RIPR) method is proposed to track the directions of multiple targets using an array of sensors. The RIPR method estimates the covariance matrix of the sensor output. The matrix is transformed from a complex-valued covariance matrix to the real-valued matrix using unitary transformations, and then the IPR method can be applied to determine the DOA of the targets. Simulation results provide substantiate evidence for the improvement over many existing methods, namely MUSIC, Root-MUSIC, and ESPRIT.