Direction of arrival estimation in the vicinity of source using vector sensor

This paper presents a novel approach for direction of arrival (DOA) estimation using vector sensors in the vicinity of source. A vector sensor, which may include antenna elements as a loop pair, a loop triad, a dipole triad or both of two triads has been introduced to be used in DOA estimation problems recently. Using the vector sensor is widely applicable technique in far field, because the complicating effects of a near field decrease accuracy of estimation dramatically. In this paper, a realistic propagation medium is modeled via Finite Difference Time Domain (FDTD) to obtain six electromagnetic field components of the incident wave field. Uni-Vector-Sensor ESPRIT method and operation of coordinate transformation are applied for the estimation of both azimuth and elevation angles in the vicinity of sources.

I. Introduction

Direction of arrival estimation problem is attractive for a wide range of applications such as radar, sonar, and wireless communications. Circular, linear or rectangular type antenna arrays are used for DOA estimations to find angles with high accuracy. Despite the fact that an increase of array's aperture size provides enhanced accuracy and resolution, a set of ambiguous direction of arrival estimations can appear if distance between the array elements is larger than half wavelength [1]. In literature, DOA estimation is achieved by using Multiple Signal Classification (MUSIC) Algorithm, Estimation of Signal Parameters via Rotational Invariance Techniques (ESPRIT) Algorithm or other types of spectral estimation techniques that use plane wave expression instead of real electromagnetic field measurements to define incident wave [2]-[4]. Custom antenna arrays gather incident wave information, eigenvalues of ESPRIT or MUSIC Algorithm use the information to find an estimation. If array geometry is available for the ambiguity, the algorithms cannot compensate their inaccurate eigenvalues.