Explicit Frequency Resolution Limit of Uniform Line Array via Scattering Information

Resolution limits and estimation performance of parameter are essential tools for evaluating the capabilities of array systems. A frequency resolution limit (FRL) for two signal sources with closely spaced frequency via information theory is proposed. We derive an explicit FRL by performing a second-order Taylor expansion on a cross-correlation coefficient. The explicit expression clearly delineates the impact of each parameter on FRL. It is noted that the proposed FRL is universally applicable, independent of any specific resolution technique. To demonstrate the interest of our method, the proposed FRL results are compared with FRL derived from other methods. The numerical simulations demonstrate that the proposed FRL in this article offers valuable guidance for the design of practical array systems.