A Simple Differential Calibration Scheme for Multi-channel Errors in DOA Estimation

The presence of gain and phase errors between array elements and corresponding channels is known to significantly degrade the performance of most high resolution direction of arrival (DOA) estimation algorithms. In this paper, a simple calibration scheme is proposed to eliminate the errors existing in the multiple channels of a direction finding (DF) system equipped with a uniform circular array (UCA). Based on differential calculations and second-order statistics, the new calibration method can compensate the differences between the channels effectively with lower implementation complexity. The design process of the scheme is described and discussed in detail. Both theoretical analyses and Monte-Carlo simulations are also provided to demonstrate the effectiveness and feasibility of the proposed scheme.