Impaired Array Diagnosis and Mitigation With Khatri–Rao Processing

Impaired array may significantly deteriorate the beampattern and consequently degrade the system performance. In this letter, we propose a signal processing scheme for impaired array diagnosis and mitigation via Khatri–Rao processing, which requires uncorrelated far-field sources to evaluate the mutual correlation between the vector signal received by the impaired array and a failure-free array. The essence is to detect impaired elements by a difference operation and then reconstruct an unpaired array through the Khatri–Rao processing. Moreover, the correlation problem due to the Khatri–Rao processing is addressed by a compressive sensing reconstruction algorithm instead of a conventional spatial smoothing algorithm to achieve improved performance. Both diagnosis and mitigation approaches require no a priori knowledge of the failed elements, but the diagnosis method needs the failure-free beampattern.