Beamspace DOA estimation method based on modified LCMV for troposcatter

Over-the-horizon(OTH) reconnaissance of radiation sources as radar can be realized by the troposcatter propagation of microwave signals. With the improving requirements of the detection coverage and resolution, the dependence among received covariance matrix caused by the troposcatter multipath fading correlation, and the receiving array manifold mismatch caused by the huge distributed scattering source are two inevitable problems. Therefore, this paper firstly provides a mutual independent multibeams arrangement according to an recently established troposcatter fading correlation model, and then proposes a modified linearly constrained minimum variance(LCMV) to compensate the diffusion phases within the array manifold, transforms the received snaps to the mutual independent beamspace and finally a beamspace direction-of-arrival (DOA) estimation method is conducted respectively. The proposed beamspace DOA estimation method is verified by the simulation results under the troposcatter multipath fading conditions.