Evaluation of effectiveness of FTTX-GPON technology-based narrowband direct modulation using shared WDM-SAC-OCDMA system

Abstract

This research presents a secure fiber-to-the-x giga passive optical network (FTTX-GPON) architecture utilizing a narrowband directly modulated vertical-cavity surface-emitting laser (VCSEL). The approach employs wavelength division multiplexing-spectral amplitude coding-optical code division multiple access (WDM-SAC-OCDMA). For feeding (4 × 2) of WDM DEMUX/MUX as an encoder of SAC-OCDMA based on identity column shifting matrix codes (ICSM), four DM-VCSELs are used in an array with a wavelength of 1480.05 nm, spaced at 0.4 nm, with bandwidths of 0.1 nm (state 1) and 0.6 nm with bandwidths of 0.15 nm (state 2). In contrast, each channel is decoded using a uniform single fiber Bragg grating (FBG). The 16-building College of Engineering at Mustaniriyah University serves as a case study to implement the suggested approach into practice. This system enhances the design, addresses performance issues, and provides coworkers access to secure data. Bit error rate (BER) and Q-factor metrics for 622.08 Mbps, 1.25 Gbps, and 2.5 Gbps are utilized to evaluate system performance. The results indicate that, for 622 Mbps with the ICSM code, the best Q-factor and BER are 23.41 and 1.69 × 10–121, respectively, while without the code, the Q-factor is 21.06 and the BER is 1.03 × 10–98 at the same setting.