Self-Calibration Direction-of-Arrival Estimation with Gain-Phase Errors Using Wideband Sources

This paper proposes an eigenstructure-based self-calibration direction-of-arrival (DOA) estimation algorithm tailored for wideband sources in the presence of gain and phase errors. Invoking the principles of narrowband self-calibration DOA estimation methods, we give an objective function based on multi-frequency snapshots and derive formulas for the alternate estimation of DOA and gain-phase errors. Furthermore, the proposed algorithm introduces a coarse-to-fine histogram scheme that effectively eliminates the pseudo-peak interference of incoherent averaging, thereby improving the estimation accuracy. To evaluate the accuracy of the DOA and gain-phase estimation, we derive the wideband self-calibration Cramér-Rao bound as a theoretical benchmark. Numerical simulations demonstrate that the proposed algorithm can handle both linear and nonlinear arrays, and improve self-calibration performance by utilizing multi-frequency snapshots.