基于ROADM级联的概率成型光传输方法北大核心CSCD

针对概率成型双偏振64-正交幅度调制相干光传输系统,实验研究了可重构光分插复用器(reconfigurable optical add-drop multiplexer,ROADM)级联引起的带宽变窄对系统比特级可实现信息速率(bit-wise achievable information rate,BW AIR)的影响。发射端采用基于麦克斯韦玻尔兹曼分布的3个概率成型分布信号。实验装置包括概率成型符号序列的产生、模拟ROADM级联引起整体频率响应带宽变窄的可变带宽光滤波器、简化检测和BW AIR计算。结果表明:对于不同的星座熵,带宽变窄的影响是相似的;对于给定光信噪比,产生最大BW AIR的星座熵取决于ROADM级联导致带宽变窄的程度。通过选择合适的概率成型星座分布,系统可获得最大化BW AIR。

Probabilistically shaped optical transmission method based on cascaded ROADM

Aiming at the probabilistically shaped dual-polarization 64-ary quadrature amplitude modulation in coherent optical transmission systems, the impact of bandwidth narrowing caused by cascaded reconfigurable optical add-drop multiplexer (ROADM) on bit-wise achievable information rate (BW AIR) was experimentally studied. The three probabilistically shaped distributed signals based on Maxwell-Boltzmann distribution were adopted by transmitter. The experimental device included the generation of probabilistically shaped symbol sequence, the variable bandwidth optical filters that simulated ROADM cascade narrowing the overall frequency response bandwidth, and the simplified detection as well as the BW AIR calculation. The results show that the impact of the bandwidth narrowing is similar for different constellation entropies, and for the given optical signal-to-noise ratio (OSNR), the constellation entropy which produces the maximum BW AIR depends on the extent of bandwidth narrowing caused by cascaded ROADM. Finally, the BW AIR can be maximized by choosing the appropriate probabilistically shaped constellation distribution.