Local distinguishability of Bell-type states

We consider the following scenario: a bipartite quantum state is prepared in one of the four Bell-type states. Each qubit is possessed by the spatially separated party, and the parties wish to distinguish between the four Bell-type states. To date, it is not possible to distinguish between the four orthonormal Bell-type states without entanglement-assisted discrimination by means of local operations and classical communication (LOCC). In this paper, we demonstrate the distinguishability of orthonormal Bell-type states with certainty by using LOCC, but no particle is exchanged between the two parties. We start with the local distinguishability of the orthogonal Bell-type states and generalize it for non-orthogonal Bell-type states with nonzero fidelity.