Xiao Zhuopeng, Zhuge Qunbi, Fu Songnian, Zhang Fangyuan, Qiu Meng, Tang Ming, Liu Deming, Plant David V
Opt Express. 2017 Oct 30;25(22):27824-27833. doi: 10.1364/OE.25.027824.
A split digital backpropagation (DBP) scheme for digital subcarrier-multiplexing (SCM) transmissions, denoted as SSDBP, is proposed and studied in both experiments and simulations. The implementation of the SSDBP is split at the transmitter and the receiver, leveraging existing chromatic dispersion (CD) compensation blocks to reduce complexity. We experimentally demonstrate that the SSDBP, with a complexity reduction up to 50% compared to the original receiver based SCM-DBP, can achieve a nonlinear compensation Q gain of 0.7-dB and 0.9-dB for 1920-km and 2880-km 34.94-GBd single channel PDM-16QAM transmissions, respectively. The maximum reach can be extended by 31.6% using 2-step SSDBP with only 27.5 complex multiplications per sample. Meanwhile, using 3-step SSDBP, the reach extension can be increased to 40.8%. The benefit of implementing part of SSDBP at the transmitter is experimentally validated with 0.1-dB Q improvement at 4-dBm launch power. We also numerically investigate the impact of the digital-to-analog converter (DAC) resolution and fiber parameter uncertainties on the nonlinear compensation performance of the SSDBP.
本文提出了一种用于数字子载波复用（SCM）传输的分裂数字反向传播（DBP）方案，称为SSDBP，并通过实验和仿真进行了研究。SSDBP的实现分别在发射机和接收机处进行拆分，利用现有的色散（CD）补偿模块来降低复杂度。我们通过实验证明，与基于原始接收机的SCM-DBP相比，SSDBP的复杂度降低了50%，对于1920公里和2880公里的34.94吉波特单通道偏振复用16正交幅度调制（PDM-16QAM）传输，其非线性补偿Q增益分别可达0.7分贝和0.9分贝。使用每样本仅27.5次复数乘法的两步SSDBP，最大传输距离可延长31.6%。同时，使用三步SSDBP，传输距离的延长可增加到40.8%。在4毫瓦发射功率下，通过实验验证了在发射机处实现部分SSDBP的好处，即Q值提高了0.1分贝。我们还通过数值研究了数模转换器（DAC）分辨率和光纤参数不确定性对SSDBP非线性补偿性能的影响。
