DOA estimation of non-circular signals based on iterative soft thresholding algorithm

Based on compressed sensing technology, a DOA estimation algorithm for reconstructing the original signal is proposed. First, the over-complete dictionary of signal vectors is established based on the sparsity of signals in spatial domain. The DOA estimation problem is transformed into sparse signals reconstruction problem, and signals in spatial domain are reconstructed using iterative soft thresholding (IST) algorithm. At the same time, combined with the second-order statistical characteristic of non-circular signal, the array is virtual extended, and the spectrum estimation is performed by MUSIC algorithm. In addition, in order to further distinguish coherent signals, spatial smoothing technology is added to the algorithm. The simulation results show that the proposed algorithm can effectively resolve incoherent signals and coherent signals under small snapshots and low SNR.