Multi-carrier optical communication schemes are attractive for high-speed mobile fronthaul networks, edge cloud computing and passive optical networks. Compared with conventional orthogonal frequency-division multiplexing (OFDM), universal filter multi-carrier (UFMC) can shape the spectrum of the transmitted signal by introducing universal filter banks. Meanwhile, probabilistic shaping (PS) can make full use of achieved signal-to-noise ratio (SNR) to adaptively adjust the entropy loading according to the measured SNR of each subchannel. However, the significant amount of required distribution matcher (DM) is challenging in the practical implementation. In this work, we experimentally demonstrated 12.5-GBd and 25-GBd PS-UFMC transmissions with approximate 10-GHz bandwidth-limited system over 30-km standard single mode fiber. Due to the sharp cutoff frequency-response of filters, the effect of the frequency decaying in the 25-GBd OFDM system has been eliminated in the UFMC system. Consequently, each subband has similar SNR and therefore the number of required DMs is reduced. Moreover, considering the receiver complexity constraints, the improved bit error ratio performance was achieved by optimizing the allocation of data subbands to mitigate inter symbol interference caused by the dispersion of transmitted fiber.

中文翻译：

---

正交频分复用与通用滤波器多载波传输的实验比较


多载波光通信方案对于高速移动前传网络、边缘云计算和无源光网络具有吸引力。与传统的正交频分复用（OFDM）相比，通用滤波器多载波（UFMC）可以通过引入通用滤波器组来对传输信号的频谱进行整形。同时，概率整形（PS）可以充分利用所实现的信噪比（SNR），根据测量的每个子通道的SNR自适应地调整熵加载。然而，所需的大量分布匹配器（DM）在实际实施中具有挑战性。在这项工作中，我们通过实验演示了 30 公里标准单模光纤上约 10 GHz 带宽限制系统的 12.5 GBd 和 25 GBd PS-UFMC 传输。由于滤波器具有尖锐的截止频率响应，25GBd OFDM系统中频率衰减的影响在UFMC系统中已被消除。因此，每个子带具有相似的 SNR，从而减少了所需 DM 的数量。此外，考虑到接收机复杂度的限制，通过优化数据子带的分配来减轻传输光纤色散引起的符号间干扰，从而提高了误码率性能。