Code development for simultaneous in-band transmission of both S AC-Optical CDMA and WDM channels

Code pulses of spectral amplitude coding (SAC)-optical code division multiple-access (OCDMA) are overlaid onto a multichannel wavelength division multiplexing (WDM) system. Modified quadratic congruence (MQC) codes are developed as the signature codes for the SAC/OCDMA system to avoid the overlapping between signals of both systems. In addition, simultaneous transmission of both optical CDMA users and WDM users on the same band is investigated using a network simulation. Our results are compared to traditional non-hybrid systems. It is concluded that the proposed hybrid scheme achieves performance that is slightly worse than that for the non-hybrid scheme. Furthermore, it provides enhanced data confidentiality as compared to the scheme with SAC/OCDMA only because WDM signals perform a partial masking over encoded signals.