Impact of dispersion on the performance of optical CDMA transmission system

The impact of fiber chromatic dispersion on the bit error rate (BER) performance of a direct sequence optical code-division multiple-access system is analyzed based on the coupled nonlinear Schrodinger equation (CNLSE). The presented to evaluate considering the expression r of the chromatic dispersion, which will be good for the analysis of the BER. The numerical results show that the system suffers a power penalty of 4.8 dB corresponding to chromatic dispersion index, r =0.4 for seven-chip m-sequence, at a BER of 10^-9. It is further noticed that the number of simultaneous users are limited to 24 for r =0.4 and 20 for r =0.6, for 31-chip m-sequence, at 6-dB power penalty. The result presents that the performance of monopole code division multiple access system impacted by chromatic dispersion is worst. It shows that the bigger r, the less user accessed at the same conditions.