Decision-point steering in optical fibre communication systems: theory

In a digital optical transmission system, the decision threshold, the sampling instant and the gain of the avalanche photodiode need to be maintained at their optimum values in order to maintain a minimum bit error ratio. The authors consider in detail the theory of steering these three parameters while pseudoerror monitoring is used to monitor the system performance, and they show that this decision-point steering can allow the optical link to maintain its performance under system variations, thus allowing a reduction in the system power margin that needs to be allocated