EDFA and p.i.n noise in optical orthogonal CDMA systems with optical hardlimiters

The performance of the optical orthogonal code-division multiple-access system using optical hardlimiter(s) with p.i.n photodetector and erbium-doped fiber amplifier (EDFA) to overcome losses is investigated using saddlepoint approximation, an accurate method for computing small errors. It shows that, with optical hardlimiter(s), the system performance considering EDFA and p.i.n noise could be significantly improved. Remarkably, while the system with single optical hardlimiter is even more sensitive to parameter settings like amplifier gain, detector threshold than the system without optical hardlimiter, the one with double optical hardlimiters allows us to have a wide range to select such parameters with the same conditions.