An Alternative Approach for Angle of Arrival Estimation

Abstract

The Multiple Signal Classification (MUSIC) algorithm is the most popular algorithm to estimate the Angle of Arrival (AOA) of the received signals. This algorithm is based on the calculation of thermal noise Eigen values and their corresponding Eigen vectors and then using them in a matrix form in the MUSIC direction finding (DF) formula. All researches in this field assumed isotropic sensors for array antennas. But for practical application in V/UHF, a practical antenna is to be used like half-wave dipole or any type of wired antenna. When MUSIC algorithm is tested with a well-known half-wave dipole which has a directive pattern in E-plane, a false reading is raised from the two angles coincide with the dipole element axis. It is found that the MUSIC algorithm does not take into consideration the nulls that result from the pattern multiplication between array factor AF (θ) and element pattern f (θ). This paper suggests an alternative approach for angle of arrival estimation. A new DF formula is derived. The suggested approach is based on the use of modified array processor in conjunction with minimum noise variance constrain algorithm as an angle of arrival estimator in spite of interference canceller as it is used for. The results show that the alternative approach gives a quite good result without any false reading or any degradation in the performance of AOA estimation.