Robust adaptive array beamforming with random error in cycle frequency

By exploiting cyclostationary properties, the SCORE algorithms presented by Agee et al. (1990) have been shown to be effective in performing adaptive beamforming without requiring the direction vector of the desired signal. However, these algorithms suffer from severe performance degradation in the presence of a random error in cycle frequency. The authors first establish a statistical model of the cyclic correlation matrix when the random error exists. According to this statistical model, two robust methods based on the SCORE algorithms are developed to achieve robust adaptive beamforming against random error. Analytical formulas are then derived for evaluating the performance of the proposed methods. Several simulation examples are also presented for confirming the theoretical analysis and showing the effectiveness of the proposed methods