Derivative constrained Noncircularity-rate Maximization robust beamforming

This paper proposes an extension of the NOncircularity Rate Maximization (NORM) beamformer that takes into account noncircular interferences. The main idea of the new approach is to utilize the spatial diversity and noncircularity dissimilarity between the desired signal and interferences plus noise simultaneously. For this purpose, the weight vector is designed by maximizing the non-circularity rate of desired signal with imposing derivative constraints on the interference directions. The proposed derivative constrained NORM algorithm could broaden the width of pattern null, therefore it provides robustness in the presence of noncircular interferences. Besides that, the new method could also be adjusted to apply in rapidly moving jammer environments, without the requirement of desired signal-free sample data. Numerical examples are included to illustrate the performance of the proposed beamformer.