Large antenna arrays for optimal direction finding

A procedure has been recently developed that computes the optimal sensors coordinates of the ambiguity-free antenna array for omnidirectional direction of arrival estimation. The procedure has an exponential complexity, motivating the simplification presented in this paper. This is made possible by exploiting some experimental observations, namely the fact that the optimal omnidirectional array has an axis symmetry and follows a concave curve. Complexity is drastically reduced and array optimization is conducted for large array sizes. As a conclusion, it is shown that, as the number of sensors increases, the Cramer-Rao bound achieved by the optimal arrays is 29% lower than that of the equivalent uniform circular arrays.