Analytical results on back propagation nonlinear compensator with coherent detection
Takahito Tanimura1, Markus Nölle, Johannes Karl Fischer
1Fraunhofer Institute for Telecommunications Heinrich Hertz Institute, Department of Photonic Networks and Systems, Einsteinufer 37, 10587 Berlin, Germany. t.tanimura@m.ieice.org
Optics Express
|December 25, 2012
Summary
Digital nonlinear compensators improve optical signal-to-noise ratio (OSNR) in dispersion uncompensated links. An upper boundary for OSNR improvement, dependent on fiber parameters and bandwidth, is derived for practical system conditions.
Area of Science:
- Optical communications engineering
- Signal processing
Background:
- Dispersion uncompensated links suffer from nonlinear impairments.
- Digital nonlinear compensators offer a potential solution to mitigate these impairments.
Purpose of the Study:
- To derive analytic formulas for the effective optical signal-to-noise ratio (OSNR) improvement.
- To analyze the impact of nonlinear signal-to-signal and signal-to-noise interactions.
Main Methods:
- Derivation of analytic formulas assuming Gaussian distributed nonlinear noise.
- Analysis of weak nonlinear signal-to-noise interaction limits.
- Numerical simulations for validation.
Main Results:
- An upper boundary for OSNR improvement was derived.
- This boundary depends on fiber parameters, WDM signal bandwidth, and backpropagation bandwidth.
- Dependency on different fiber types and practical system conditions were discussed.
Conclusions:
- The derived analytical formulas provide a theoretical framework for OSNR improvement.
- The findings are validated by numerical simulations, confirming their practical relevance.
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