Performance limitations of an optical CDMA system impaired by fiber chromatic dispersion

A theoretical analysis is presented to evaluate the impact of fiber chromatic dispersion on the bit error rate performance of a direct sequence optical code division multiple access (DS-OCDMA) system with intensity modulation and direct detection (IM/DD) transmission link using sequence inversion keyed (SIK) optical correlator. Computed results are evaluated at a chip rate of 10 Gchip/sec. The results show that the system suffers a power penalty of 3.48 dB corresponding to fiber chromatic dispersion index,γ=0.3 for a 7chip m-sequence, at a bit error rate (BER) of 10^-9. It is further investigated that the number of simultaneous users are limited to 11 for γ=0.3 and 6 for γ=0.59 for 31 chip gold sequence, at a power penalty of 2 dB and a BER of 10^-9. The analytical results are validated by computer simulation.