We propose a possible improvement for optical hybrid transmission systems, based on 40G differential quadrature shift Keying (DQPSK) and 10G differential phase shift keying (DPSK) received by means of a Gaussian narrow filter. We report a reduced cross phase modulation (XPM), at the cost of a slightly more complex setup. This technique is especially effective for systems with low inline dispersion and offers similar performances on different types of fiber.