基于自相干正交频分复用的长距离波分复用无源光网络研究

Due to its attractive features, i.e., large dedicated bandwidth, high security and easy upgrade, a WDM-PON is regarded as a very promising technology for the next generation optical access network. However, it has four challenging technical issues to be addressed: symmetric and high bit rates, remodulation-based colorless ONU, single fiber bidirectional transmission, and long reach passive transmission. This project will try to tackle those four issues by leveraging on self-coherent optical orthogonal frequency-division multiplexing (SCO-OFDM). SCO-OFDM can achieve similar performance with the conventional coherent optical orthogonal frequency-division multiplexing (CO-OFDM), but requires neither phase noise compensation nor frequency offset compensation. This project will conduct comprehensive study on the theory of SCO-OFDM, and with this basis the whole system will be further designed. We will verify the designed system via both Matlab simulation and experiments. After solving some key scientific problems, i.e., optimization of the SCO-OFDM parameters, synchronization and equalization of the SCO-OFDM signal, and effective suppression of Rayleigh noise, we can provide some forward-looking results, both theoretically and experimentally, which are expected to serve as guidelines for the practical implementation of the designed system. Our project will also pave new ways for the research and design of our country's next generation optical access networks.

波分复用无源光网络（WDM-PON）由于具有高带宽、高安全性、升级容易等优点而被视为非常有潜力的下一代光接入技术。但是WDM-PON尚面临亟待解决的四个技术难点：上、下行对称的高速率传输、基于重调制的无色ONU、单纤双向传输和无源长距离传输。本项目将探索使用自相干光正交频分复用（SCO-OFDM）来解决上述四个技术难点。SCO-OFDM具有和传统的相干光正交频分复用（CO-OFDM）相似的性能，但不需相位噪声补偿和频率偏差补偿。本项目将在理论上对SCO-OFDM进行全面的研究，并以此为基础进行系统设计。我们将对所设计系统进行Matlab仿真和实验研究，以证实其可行性。我们将通过解决SCO-OFDM相关参数的优化，SCO-OFDM信号的同步和均衡，以及对雷利噪声的有效抑制等关键科学问题，为系统的具体实现提供具有指导意义和前瞻性的理论和实验结果，同时也为我国的下一代光接入网的研发提供新思路。

随着宽带业务的普及，光接入网是未来接入技术的必然趋势。波分复用无源光网络（WDM-PON）由于具有高带宽、高安全性、升级容易等优点而被视为非常有潜力的下一代光接入技术。但是WDM-PON尚存在亟待解决的四个技术难点：上、下行对称的高速率传输、基于重调制的无色ONU、单纤双向传输和无源长距离传输。本项目探索使用自相干光正交频分复用（SCO-OFDM）来解决上述四个技术难点。SCO-OFDM具有和传统的相干光正交频分复用（CO-OFDM）相似的性能，但不需相位噪声补偿和频率偏差补偿。本项目在理论上对SCO-OFDM进行了全面的研究，并以此为基础进行系统设计。我们设计了一种新颖的WDM-PON体系结构，该方案通过SCO-OFDM重调制技术可以同时抑制重调制串扰和雷利噪声串扰。我们实验验证了基于SCO-OFDM的OUN的确不需要进行频偏补偿和相位噪声补偿，可以大大降低ONU的复杂度和功耗。在我们的原理展示性实验中实现了单根25公里光纤双向传输12.5Gb/s的OFDM信号。我们希望在将来通过光子集成技术进一步简化ONU结构。