Underdetermined DOA estimation of wideband non-stationary signals based on ANM

An underdetermined direction-of-arrival (DOA) estimation method is proposed for wideband non-stationary signals based on atomic norm minimization. In scenarios where signals exhibit completely overlapped time-frequency distributions (TFDs), the spatial time-frequency distribution (STFD) matrix becomes rank deficient, making it impossible to separate signals based on their time-frequency characteristics. This proposed method uses multiple snapshots atom norm minimization to achieve an ideal average STFD matrix and enables underdetermined DOA estimations of wideband non-stationary signals with completely overlapped TFDs, without aperture loss or the need for arrays to possess spatial translation invariant structures. Moreover, the proposed method involves interpolating the sparse array into a virtual uniform linear array to enhance array processing degree freedom. Simulation results illustrate the efficacy of the proposed method.