Wideband gaussian source processing using a linear nested array

Based on a recently proposed linear nested array, we consider the problem of source number detection and direction of arrival estimation for wideband Gaussian sources. This array provides $O(N^{2})$ degrees of freedom with $O(N)$ sensors, enabling us to estimate $K$ sources with $N < K$ sensors. To employ the nested array for the wideband case, we propose effective strategies to apply nested-array processing to each frequency component, and combine all the spectral information of various frequencies to conduct the detection and estimation. In particular, for source detection, we propose a novel approach employing the idea of ensemble, used in machine learning and statistics. Numerical simulations demonstrate the advantages of our strategies.