  We calculate persistent current of one-dimensional rings of fermions
neglecting the spin degrees of freedom considering only nearest-neighbor
Coulomb interactions with different electron fillings in both ordered and
disordered cases. We treat the interaction exactly and find eigenenergies by
exact diagonalization of many-body Hamiltonian and compute persistent current
by numerical derivative method. We also determine Drude weight to estimate the
conducting nature of the system. From our numerical results, we obtain a
metal-insulator transition in half-filled case with increasing correlation
strength U but away from half-filling no such transition is observed even for
large U.
