Direction of arrival estimation using a sparse circular array and multiplicative beamforming

A computationally efficient method for estimating the angle of arrival of the strongest plane wave incident on a sparse circular antenna array is described. In the example investigated, the elements of the array are spaced by more than 5 1/2
\lambda
, eliminating the problems of mutual coupling. An unambiguous estimate of the angle of arrival is obtained by a beamforming approach. Results of computer simulations are presented which show the processing to be robust in the presence of noise, multipath signals, and antenna element positioning errors.