The rapid progress in video-based Internet applications is increasing the demand for efficient optical communication systems. Therefore, spectral-amplitude coding optical code-division multiple access (SAC-OCDMA) is an attractive candidate to flexibly implement the optical access networks used to deliver bandwidth-intensive networking applications. These applications such as video conferencing, 3D video, multichannel high-definition television (HDTV), and ultra high-speed Internet to residential customers are expected to become the next major success commercial applications for OCDMA system. This can be attributed to their fairness, truly asynchronous transmission with low latency, improved information security, and dynamic bandwidth assignment.
The major drawback of SAC-OCDMA systems is their inherent intensity noise originating due to the incoherency of the light source. In this invention, we propose a new detection technique named the modified-AND subtraction detection based upon dividing the spectrum of the utilized code sequence. The new technique is capable of mitigating the intensity noise impact, as well as eliminating the MAI influence. Based on MDW code, results reveal that for a BER of 1×10¿9 and data rate of 622 Mb/s, conventional AND detection can support only 13 users, whereas the modified-AND can support around 24 simultaneous users, this shows 84% increment in the number of users for the same Quality of Service (QoS).