Concentric circular-shaped electronically steerable parasitic array radiator antennas for full-azimuth directions of arrival estimation with reduced computational load

This study proposes a new uniform concentric circular (UCCA) shape of electronically steerable parasitic array radiator (ESPAR) antennas for directions of arrival (DoAs) estimation problem. The well-known estimation of signal parameters via rotational invariance techniques (ESPRIT) algorithm is adapted to this special shape of UCCA and the authors demonstrate that the resulting algorithm yields better DoAs estimation accuracy and solves the failure of estimation problem when the signals´ DoAs are in some particular sectors: notably for [0°-30°] and [160°-180°]. This approach has shown interesting performances since it can ensure good DoAs estimation over the entire azimuth plane with a low extra computational overhead. The constraints are the same imposed to the ESPRIT algorithm allowing about 66% reduction on the required computational efforts. The Cramer Rao bound on the variance of DoAs estimated by the proposed array geometry is analysed. Through simulation results, the authors demonstrate that applying ESPRIT in conjunction with the proposed antennas shape not only provides superior high-resolution localisation capabilities but also it drastically reduces computations compared with previous works.