A comparative study of modified PUSCA and paired PUSCA strategies in WDM system

In G.653 compliant fiber, four-wave mixing (FWM) is a dominant non-linear effect. Performance of optical wavelength division multiplexing (WDM) network based on G.653 fiber is affected by the generated FWM components. The paper aims to discuss the methods used to reduce the number of FWM components and make efficient utilization of bandwidth. We have earlier proposed two methods (a) modified periodically unequally spaced channel allocation (modified PUSCA) and (b) paired PUSCA. In this paper, we have compared both the methods by considering the ratio of increase in weighted average signal to FWM noise ratio to increase in bandwidth as a figure of merit. Further, the performance of paired PUSCA scheme on G.653 fiber has been compared with equally spaced channel allocation (ESCA) scheme on G.652 fiber in which FWM is not a dominant non-linear effect. We demonstrate that paired PUSCA on G.653 fiber performs better than ESCA on G.652 fiber when the number of channels is less than 30.