A Modified MUSIC Algorithm for Direction of Arrival Estimation in the Presence of Antenna Array Manifold Mismatch

We introduce a modified multiple signal classification (MUSIC) algorithm to estimate the directions of arrival (DOAs) of multiple radio frequency signals. We specifically consider an antenna array with an imperfectly calibrated array response. The modified MUSIC algorithm estimates the DOA of each signal individually after attempting to null the other signals that are present. We compare the new approach to the conventional MUSIC algorithm in simulations, and show that the new approach leads to improved performance. The new approach converges quickly and produces DOA estimates with smaller mean error and standard deviation than MUSIC over a range of incident signal separations. We recommend our approach for systems with challenging antenna placements, a time varying host platform, and limited processing capabilities.