Noncoherent Spectral/Spatial Optical CDMA System Using 2-D Diluted Perfect Difference Codes

A newly constructed code family named two-dimensional diluted perfect difference codes (2-D DPD codes) and a corresponding architecture for the optical code division multiple access (OCDMA) system are proposed in this paper. The 2-D DPD codes are derived based on the perfect difference set and the dilution method for the spectral and spatial coding application. The 2-D DPD codes have the multiuser interference (MUI) cancellation and the phase-induced intensity noise (PIIN) suppression properties. In comparison with the other 2-D codes, such as the modified quadratic congruence codes (MQC codes), the maximal-area matrices codes (M-matrices codes), or the 2-D perfect difference codes (2-D PD codes), the analytical calculation and the simulation results show that the systems with the 2-D DPD codes have better performance. The proposed system can accommodate much more total number of simultaneous users at the same bit error rate.