Low complexity digital back propagation method using phase linear approximation for nonlinear distortion compensation for long haul transmission systems
We propose a novel nonlinear distortion compensation technique using
linear phase transition approximation for long haul optical communication
system. Self-phase modulation (SPM) for phase change, and amplified
spontaneous emission (ASE) from erbium-doped fiber amplifier (EDFA)
are taken into consideration in simulation. It is confirmed that phase of
28Gbaud return to zero - quadrature phase shift keying (RZ-QPSK) signals
compensated with split-step Fourier methods (SSFM) change almost
linearly. They can be estimated using linear approximation with only two
points of any span for low computational complexity. The performance of
this technique is evaluated by bit error rate (BER) with numerical analysis.
The achieved reduction of computational amount is 70.0% when
transmission distance is 2500km and input power is 0dBm at a FEC limit of
BER < 10−3.