An Oblique Projection-Based Beamforming Method for Coherent Signals Receiving

Within a complex sea or ground surface background, multipath signals are strongly correlated or even completely coherent, which leads to signal cancellation when conventional optimal beamforming is performed. Aiming at the above problem, a coherent signal-receiving algorithm is proposed based on oblique projection technology in this paper. The direction of arrival (DOA) of incident signals is estimated firstly by the space smoothing-based MUSIC method. The composite steering vector of multipath coherent signals is then obtained utilizing the oblique projection matrix constructed with the estimated angles. The weight vector is thereby derived with the minimum variance distortionless response criteria. The proposed oblique projection-based beamformer can receive the multipath coherent signals effectively. Moreover, the proposed beamformer is more robust and converges to optimal beamformer rapidly without aperture loss. The theoretical analysis and simulation verify the validity and superiority of the proposed coherent signal beamformer.

Automated summary

This paper proposes a coherent signal receiving algorithm based on oblique projection technology to effectively receive multipath coherent signals in a complex background. The algorithm estimates the direction of arrival (DOA) of incident signals using the space smoothing-based MUSIC method and obtains the composite steering vector of multipath coherent signals by constructing an oblique projection matrix. The weight vector is then derived using the minimum variance distortionless response criteria. The proposed algorithm is shown to be effective and superior through theoretical analysis and simulations.