Performance evaluation of the second order and fourth order statistics based root MUSIC algorithms in the presence of mutual coupling

Direction finding (DF) algorithms based on polynomial rooting implicitly assume equality among the element radiation patterns. However, in real antenna arrays this equality is violated due to the phenomenon known as mutual coupling that can significantly deteriorate accuracy of the root DF algorithms. In this paper we compare robustness of the second order (SO) and fourth order (FO) statistics based root MUSIC algorithms in the presence of the various levels of mutual coupling among the elements of the uniform linear array (ULA). It has been demonstrated that FO root MUSIC algorithm exhibits significantly higher level of robustness in the presence of mutual coupling when number of sources is greater than one.