Optimally weighted ESPRIT using uniform circular arrays

We study a weighted ESPRIT method for estimating the direction cosine (of 2-D angles of incoming wave arrivals) based on uniform circular arrays. An optimum weighting matrix is found and shown to satisfy a generalized centro-Hermitian relationship. As a result, an optimally weighted ESPRIT method is formulated. For a single low (altitude) angle source, the method provides more than 3 dB reduction in estimation variance.