Effect of dispersion and nonlinearity on performance of asynchronous OCDMA systems

In order to study the influence of dispersion and nonlinearity on asynchronous optic code division multiple access(OCDMA)systems based on nonlinear Schrdinger equation, the functions of the bit error rate of an asynchronous OCDMA system with the transmission distance and the number of users were obtained by means of simulation. The results show that the performance of an asynchronous OCDMA system can be deteriorated severely by the group velocity dispersion, the third-order dispersion and nonlinear effects, especially the group velocity dispersion. Dispersed shift fiber can be used as system transmission medium so as to compensate the consequent system performance degradation.