Wavelength-division-multiplexing passive optical network (WDM-PON) has been considered as a promising next generation access network solution. A centralized light-wave colorless WDM-PON architecture based on a single feeder fiber. At the optical line terminal, differential quadrature phase shift keying (DQPSK) modulated signal at 10 Gbps is utilized for downstream transmission is proposed and demonstrated. At the optical line unit, part of the downstream signal is remodulated using an intensity modulated on/off keying technique for upstream transmission. Simulation results show that downstream and upstream signals achieved error-free transmission at 10-Gbps symmetric data rate with negligible power penalties. The proposed scheme exhibit improved tolerance to Rayleigh backscattering over 20 km standard single mode fiber.