Design of High-Capacity Spectral Amplitude Coding OCDMA System with Single Photo-Diode Detection Technique

Abstract

Performance of non-coherent optical code division multiple access (OCDMA) system is primarily deteriorated by the presence of multiple access interference (MAI) and associated phase induced intensity noise (PIIN) at the receiving photo-diode. Therefore, it is imperative to negate the effects of MAI and associated PIIN before the signal is converted to electrical domain. This paper proposes a spectral amplitude coding SAC-OCDMA system that can provide high capacity in terms of reach, bandwidth, and the number of subscribers. The proposed system utilizes single photo-diode detection (SPD) technique to recover the encoded spectrum with maximum auto- and minimum cross-correlation between the intended and interfering subscribers. Moreover, binary to spectral translation at the encoder is facilitated by enhanced multi-diagonal (EMD) code with fixed in-phase correlation property. Bit error rate analysis while using Gaussian approximation shows that the proposed setup is able to minimize MAI and PIIN while supporting 64 subscribers at 1.5 Gbps of data. For further investigation, simulation analysis using Optisystem is performed that also validates the results obtained from Gaussian approximation analysis of the proposed SAC-OCDMA system with EMD code at the encoder and SPD technique at the decoding arrangement.