Effects of modulation techniques RZ, NRZ, and CSRZ on the operation of hybrid OCDMA/WDM system for gigabit passive optical networks

Abstract

In this paper, the performance of hybrid optical code division multiple access/wavelength division multiplexing (OCDMA/WDM) system is evaluated for gigabit passive optical network (GPON). We have investigated, compared and analyzed various modulation techniques for 5 km distance with channel transmission rates at 2.5Gbps and 5 Gbps for OCDMA and WDM respectively. The Enhance Double Weight (EDW) code is used as a signature address for this system for studying the system limitations, benefits, and capabilities in order to transmit signal and handle high data traffic for the future multi gigabit optical networks. Simulation results revealed that Non-return to Zero (NRZ) modulation format provides better performance considering Bit-Error-Rate of 10E-13 and 11.608 dBm received optical power. The overall system performance using NRZ is increased by 17% and 33% against RZ and CSRZ.