A new array extension configuration method based on nesting and minimum redundancy

While the uniform linear array (ULA) is a well-known array configuration being widely used in various practical application scenarios, it also encounters numerous challenges in the field of direction-of-arrival (DOA) estimation. Specifically, it is difficult for the ULA to achieve a satisfactory DOA estimation accuracy, especially in the case of closely spaced sources. That is because that the resolvability of ULA is severely restricted by its limited DOA. To circumvent this issue and further improve the DOA estimation performance, a new array geometry is designed. Inspired by the fact that some linear sparse co-arrays can yield higher DOFs and larger array apertures, the proposed array configuration is developed by nesting two or more minimum-redundant arrays in a dedicated way. The simulation results indicate that the proposed array configuration can significantly increase the DOFs and the length of virtual array apertures, and an improved estimation accuracy can be accepted.