Modeling the impact of group velocity dispersion on the performance of 2-D WH/TS OCDMA systems

In this paper, a novel model of Gaussian pulse propagation in optical fiber is proposed to comprehensively analyze the impact of Group Velocity Dispersion (GVD) on the performance of two-dimensional wavelength hopping/time spreading optical code division multiple access (2-D WH/TS OCDMA) systems. In addition, many noise and interferences, including multiple access interference (MAI), optical beating interference (OBI), and receiverpsilas noise are included in the analysis. Besides, we propose to use the heterodyne detection receiver so that the receiverpsilas sensitivity can be improved. Analytical results show that, under the impact of GVD, the number of supportable users is extremely decreased and the maximum transmission length is remarkably shortened when the normal single mode fiber is used. The main factor that limits the system performance is time skewing. In addition, we show how the impact of GVD is relieved by dispersion-shifted fiber. For example, a system with 32 times 1 Gbit/s users can achieve a maximum transmission length of 111 km when transmitted optical power per bit is -5 dBm.