Digital backpropagation based on binary logarithmic step size distribution for fibre non‐linearity compensation

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, 1.19, and 0.71 dB over linear compensation, constant step size (CSS) DBP, and logarithmic step size DBP techniques in a 2400 km 112 Gbit/s DP‐16 quadrature amplitude modulation (QAM) 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% saving in the number of DBP calculation steps compared to the CSS DBP, which considerably reduces the computational cost since a few steps are required for effective non‐linearity compensation. This work proposes a low‐complexity digital backpropagation (DBP) implementation approach for high data rate optical transmission using a binary logarithmic step size method. The proposed scheme shows significant performance improvements over linear compensation and other DBP techniques in a 2400 km 112 Gbit/s DP‐16 QAM system, achieving a high performance above the hard‐decision forward error correction limit and extending the allowable transmission distance. The proposed approach also achieves computational cost savings by reducing the number of DBP calculation steps.