Hybrid OCDMA Over WDM system with DPSK modulation using direct and complementary subtraction detection techniques

This paper introduces a hybrid optical Code division multiplexing (OCDMA) over wavelength division multiplexing (WDM) system with differential phase shift keying (DPSK) modulation using direct and complementary subtraction detection techniques. Two different technologies namely, OCDMA and WDM are combined together as a hybrid system to increase the transmission capacity, security and reliability of the network. Multiple access interference (MAI) is one of the main factors that degrade the performance of such hybrid system. The modified double weight (MDW) code is used as a signature address code for the system. The application of direct and complementary subtraction detection techniques at data bit rate of 1Gbps are compared. OptiSystem version 12 is used for simulation to investigate the proposed system. Simulation results reveal that the complementary subtraction technique provides better BER vs distance performance than the direct detection technique.