Impaired Sensor Diagnosis, Beamforming, and DOA Estimation With Difference Co-Array Processing

Impaired sensors will significantly deteriorate phased-array beampattern, and consequently degrade the output signal-to-interference plus noise ratio (SINR) and direction-of-arrival (DOA) estimation performance. In this paper, we propose a signal-processing scheme for impaired phased-arrays, including beamforming and DOA estimation as well as array diagnosis. The essence is to reconstruct an unimpaired array through the Khatri-Rao product-based difference co-array processing and exploiting the power of the received signal instead of the signal amplitude. Superiority of the proposed approach over conventional methods is demonstrated by examining the array beampattern, output SINR, and DOA estimation performance. Furthermore, we devise a diagnosis strategy to detect the sensors with defect in the array. Our solution requires no a priori knowledge of the malfunctioning elements and allows some of them with complete failure, and its effectiveness is verified via computer simulation.