A Fourth-Order Cumulant-Based Multi-Sources DOA Estimation in UAV Collaborative Systems

Multi-sources Direction of Arrival (DOA) estimation based on Unmanned Aerial Vehicle (UAV) draws much attention for its flexibility and practicability. Meanwhile, the UAV collaborative technology can be used to guarantee the spatial Degree of Freedom (DOF), but it is always puzzled by the imprecise array structure and the strict demand of Radio Frequency (RF) chains calibration. The random amplitude and phase differences among the units deeply disturb the DOA estimation. To handle this random problem, a unique UAV network is designed, and a fourth-order cumulant-based multi-sources DOA estimation algorithm is proposed in this letter. The network consists of one main unit with two antennas and several assistant units with one antenna, the main unit provides the effective amplitude and phase information and the assistant units are used to ensure the spatial DOF. Therefore, both the array structure information and RF chain calibration of assistant units are not needed. The simulation results verify that the proposed algorithm is effective for multi-sources DOA estimation even with random amplitude and phase differences among the units.