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Time domain OCDMA PON architecture for 2048 optical network units

Optical code-division multiple access (OCDMA) is one of the alternatives to time-division multiple access (TDM) and wavelength-division multiple (WDM) access in passive optical network (PON) systems as in this multiple users can share the same channel at the same time by assigning different codes to each user. This paper presents basic architecture, working principle, advantage, and disadvantage of the OCDMA system in details. Next, Time domain OCDMA PON architecture for 2048 optical network units (ONUs) at 60 km reach at 2.5 Gb/s bit rate is proposed. The simulated model is investigated for different number of users and transmission distance in terms of BER and Q-factor. The result shows that the simulated model can support up to 2048 users with acceptable BER and Q-factor. Also, multi-access interference effect on proposed architecture is studied. The simulation is carried out using Optsim.