Chen Yiqin, Hu Rong, Yang Qi, Luo Ming, Yu Shaohua, Li Wei
Opt Express. 2015 May 4;23(9):12065-71. doi: 10.1364/OE.23.012065.
We propose a novel fading-free direct-detection optical orthogonal frequency division multiplexing (DDO-OFDM) scheme for 100-Gb/s medium-reach transmission. In the proposed scheme, we adopts two bands spaced at 100-GHz to accommodate the same complex-valued OFDM signal. However, the signals are coupled with a pair of orthogonal optical carriers. By doing so, real and imaginary parts of the complex-valued OFDM signal can be recovered from the two bands, respectively. We also propose a cost-effective scheme to generate such DDO-OFDM signal using an optical 90-degree hybrid and an optical I/Q modulator. The advantage of the proposed method is that it is fading-free, and the electrical spectral efficiency (SE) is doubled compared to traditional direct-detection method. Finally, we experimentally demonstrated a 101-Gb/s dual-band transmission over 320-km SSMF within only 30-GHz electrical bandwidth, which is highly competitive in both capacity and cost.
我们提出了一种用于100 Gb/s中距离传输的新型无衰落直接检测光正交频分复用（DDO-OFDM）方案。在所提出的方案中，我们采用两个间隔为100 GHz的频段来承载相同的复值OFDM信号。然而，这些信号与一对正交光载波进行耦合。通过这样做，复值OFDM信号的实部和虚部分别可以从这两个频段中恢复。我们还提出了一种经济高效的方案，使用一个光学90度混合器和一个光学I/Q调制器来生成这种DDO-OFDM信号。所提方法的优点是它无衰落，并且与传统直接检测方法相比，电频谱效率（SE）提高了一倍。最后，我们通过实验证明了在仅30 GHz电带宽内，在320 km的单模光纤（SSMF）上实现了101 Gb/s的双频段传输，这在容量和成本方面都具有很强的竞争力。
