DOA Estimation With a Rotatable Sparse Array via Adaptive Multi-View Fusion

This letter proposes an adaptive rotation strategy (ARS) to resolve grating-lobe ambiguity in sparse arrays with large inter-element spacing. By exploiting the invariance of the true direction of arrival (DOA) across rotations, ARS fuses candidates from multi-view spatial spectra. A sequential decision framework with adaptive feedback introduces views only when required, reducing measurement overhead while ensuring reliable disambiguation. Simulation results demonstrate that the proposed scheme can approach the Cramér–Rao bound (CRB).