Cramer-Rao Bound of Direction Finding Using a Uniform Hexagonal Array

Abstract

Direction-of-arrival (DOA) estimation is a key area of sensor array processing which is encountered in many important engineering applications. Although various studies have focused on the uniform hexagonal array for direction nding, there is a scanty use of the uniform hexagonal array in conjunction with Cram er-Rao bound for direction nding estimation. The advantage of Cram er- Rao bound based on the uniform hexagonal array: overcome the problem of unwanted radiation in undesired directions. In this paper, the direction-of-arrival estimation of Cram er-Rao bound based on the uniform hexagonal array was studied. The proposed approach concentrated on deriving the array manifold vector for the uniform hexagonal array and Cram er-Rao bound of the uniform hexagonal array. The Cram er-Rao bound based on the uniform hexagonal array was compared with Cram er-Rao bound based on the uniform circular array. The conclusions are as follows. The Cram er-Rao bound of uniform hexagonal array decreases with an increase in the number of sensors. The comparison between the uniform hexagonal array and uniform circular array shows that the Cram er-Rao bound of the uniform hexagonal array was slightly higher as compared to the Cram er-Rao bound of the uniform circular array. The analytical results are supported by graphical representation.