Performance improvement of fibre-optic code-division multiple-access systems by using error-correction codes

In code-division multiple-access (CDMA) systems using all-optical signal processing, the optical multiple-access interference (OMAI) degrades the system performance and can ultimately limit the number of active users. To reduce the effect of OMAI, error-correction codes are used in both asynchronous and synchronous fibre-optic CDMA systems. It is shown that the use of asymmetric error-correction binary block codes can not only effectively reduce the bit-error rate, but also increase the maximum number of active users in a constant-bandwidth network more efficiently than using symmetric error-correction binary block codes. Therefore, this permits implementation of a cost-effective fibre-optic CDMA network