Model-aided Deep Neural Network for Source Number Detection

Source number detection is a critical problem in array signal processing. Conventional model-driven methods e.g., Akaikes information criterion and minimum description length, suffer from severe performance degradation when the number of samples is small or the signal-to-noise ratio is low. In this letter, we exploit the model-aided based deep neural network to estimate the source number. Specifically, we propose two eigenvalue based networks, i.e., a regression network (ERNet) and a classification network (ECNet), for source number detection, where the eigenvalues of the received signal covariance matrix and the source number are used as the input and the label of the networks, respectively. Furthermore, ERNet and ECNet can be easily generalized to handle coherent sources by adopting, e.g., the forward-backward spatial smoothing technique. Numerical results are included to showcase the remarkable improvements of ERNet and ECNet over the existing methods.