Double-constraint flexible tree search-based orthogonal matching pursuit for DOA estimation using dynamic sensor arrays

Greedy algorithms have leveraged sparse signal models for parameter estimation purposes in applications including bearing estimation and direction-of-arrival (DOA) estimation. A dictionary whose elements correspond to observations for a sampling of the angle space is used for sparse approximation of the received signals; the resulting sparse coefficient vector's support identifies the DOA estimates. Increasing the angle space sampling resolution provides better sparse approximations for arbitrary observations, while the resulting high dictionary coherence hampers the performance of standard sparse approximation, preventing accurate DOA estimation. To alleviate this shortcoming, in the each iteration, we use the structured sparsity model that keeps high coherent and close spacing dictionary elements. Besides, the proposed approach allows exploitation of the array orientation diversity (achievable via array dynamics) in the compressive sensing framework to address challenging array signal processing problems such as left-right ambiguity and poor estimation performance. And the simulation results show that our proposed algorithm can offer significantly improved performance in single-snapshot scenario with multiple sources.