Non-coherent DOA estimation of off-grid signals with uniform circular arrays

Recently, some non-coherent DOA estimation methods are presented under a sparse phase retrieval framework, where DOAs of incident signals are assumed to be on the predefined grid points. However, this may not be correct in practice; in order to address this issue, an off-grid model involved with a bias vector is proposed and an efficient two-step method based on this model is developed. In addition, instead of using ULAs, uniform circular arrays (UCAs) are employed in order to overcome the ambiguities arising in non-coherent measurements, as analysed in detail. Numerical simulations show that, compared to on-grid model with a denser grid points, the off-grid model with a coarse grid can achieve a better performance with a lower computational complexity.