On error-correction coding for CDMA PON

Optical-code-division multiple access (OCDMA) has been investigated as a multiple-access technique for a long time, but so far, it has not reached any practical success. We investigate the performance of low-complexity OCDMA systems with a realistic model of noise and interference; the main limitation of the system is beat noise. To improve the performance, we consider forward-error correction (FEC) and soft decoding using standard error-correcting codes. The achievable error rates are evaluated using simulations and show significant improvement when FEC is used. The results also show that frequency-hopping systems perform better than temporally coded systems when beat noise is taken into account.