IRZ-Manchester coding for downstream signal modulation in an ONU-source-free WDM-PON

►One new code IRZ-Manchester code is proposed for re-modulation PON. ►There are no ER restrictions for IRZ-Manchester coded downstream when the DPSK overlay or the re-modulated upstream signal is imposed on. ►Better performance of IRZ-Manchester coding and modulation scheme in supporting optical ASK re-modulation in comparison with Manchester coding or IRZ modulation in the simulation.