Abstract:In the array processing problem, the high-order cumulants not only are capable to reduce the Gaussian noises but also have the aperture extension property. The method of the aperture extension using the fourth-order cumulants are studied and the structure of the corresponding virtual array are presented in this paper. The fourth-order coherent problem in the application in the narrow-band direction-finding system is given and analyzed. We obtain the array aperture extension condition of the fourth-order cumulant-based method to the multiple sources case. The numerical results support the analytic results.