Abstract
Nonlinearity mitigation based on the enhanced
split-step Fourier method (ESSFM) for the implementation
of low-complexity digital backpropagation (DBP) is investigated
and experimentally demonstrated. After reviewing
the main computational aspects of DBP and of the conventional
split-step Fourier method (SSFM), the ESSFM for
dual-polarization signals is introduced. Computational complexity,
latency, and power consumption of DBP based on
the SSFM and ESSFM algorithms are estimated and compared.
Effective low-complexity nonlinearity mitigation in
a 112 Gb/s polarization-multiplexed QPSK system is experimentally
demonstrated by using a single-step DBP based
on the ESSFM. The proposed DBP implementation requires only a single step of the ESSFM algorithm to achieve a transmission
distance of 3200 km over a dispersion-unmanaged
link. In comparison, a conventional DBP implementation
requires 20 steps of the SSFM algorithm to achieve the same
performance. An analysis of the computational complexity
and structure of the two algorithms reveals that the overall
complexity and power consumption of DBP are reduced by
a factor of 16 with respect to a conventional implementation,
while the computation time is reduced by a factor of
20. Similar complexity reductions can be obtained at longer
distances if higher error probabilities are acceptable. The
results indicate that the proposed algorithm enables a practical
and effective implementation of DBP in real-time optical
receivers, with only a moderate increase in the computational
complexity, power consumption, and latency with respect to
a simple feed-forward equalizer for bulk dispersion compensation.
Original language | English |
---|---|
Journal | Photonic Network Communications |
Volume | 31 |
Issue number | 3 |
Number of pages | 10 |
ISSN | 1387-974X |
DOIs | |
Publication status | Published - 2015 |
Keywords
- Fiber-optic systems
- Fiber nonlinearity
- Digital backpropagation