Digital Backpropagation Based on Binary Logarithmic Step Size
Distribution for Fiber Nonlinearity Compensation
Abstract
Capacity crunch has become critical in recent years as commercial
communication systems approach their theoretical data rate limits. This
work presents a low-complexity digital backpropagation (DBP)
implementation approach based on step size distribution that uses a
binary logarithmic step size method to achieve high data rate optical
transmission. The proposed scheme shows performance improvements (∆Q) of
2.36 dB, 1.19 dB, and 0.71 dB over linear compensation, constant step
size DBP, and logarithmic step size DBP techniques in a 2400 km 112
Gbit/s DP-16QAM system, respectively. At 13 dBm, a high performance (Q)
of 10.9 dB (BER = 2.25×10-4) is achieved, above the 3.80×10-3
hard-decision forward error correction (HD-FEC) limit, using the
proposed scheme. Also, the allowable transmission distance is extended
by 960 km at the HD-FEC limit over the linear compensation technique.
The optimization achieves a 38% savings in the number of DBP
calculation steps compared to the constant step size DBP, which
considerably reduces the computational cost since a few steps are
required for effective nonlinearity compensation.