In this paper, a novel nested array is proposed for direction of arrival (DOA) estimation of noncircular signals. By using the noncircular property, we can get a virtual array composed of difference coarray (DCA) and sum coarray (SCA). Specifically, we give the properties of DCA and SCA for the generalized translational nested array first. Then, based on the relationship between DCA and SCA, an optimal translational nested array with increased degrees of freedom (DOFs) is constructed. To extend the physical array aperture, we move part of sensors in the translational nested array to the mirrored locations. Accordingly, the novel nested array with increased DOFs and physical array aperture is obtained. Finally, superiority of the proposed array is demonstrated by simulation experiments.