Efficient Joint Carrier Frequency Offset and Phase Noise Compensation Scheme for High-Speed Coherent Optical OFDM Systems
Efficient Joint Carrier Frequency Offset and Phase Noise Compensation Scheme for High-Speed Coherent Optical OFDM Systems
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DOI：
10.1109/jlt.2013.2257688
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发表时间：
2013-06
影响因子：
4.7
通讯作者：
Xian Zhou;Xiaolong Yang;Rui Li;Keping Long
中科院分区：
文献类型：
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作者：
Xian Zhou;Xiaolong Yang;Rui Li;Keping Long
对激光线宽引起的载波间干扰（ICI）的脆弱敏感性长期以来一直被认为是相干光正交频分复用（CO-OFDM）系统的一个主要问题。在现有的相位噪声补偿算法中，射频导频辅助相位恢复（RAPR）方法对激光线宽表现出更好的补偿能力。然而，由于载波频率偏移（CFO）的影响，RAPR可能无法提取接收器处预先插入的RF导频。因此，在执行 RAPR 之前需要实施有效的频偏估计 (FOE)。考虑到传统FOE算法不仅计算复杂度高，更重要的是无法与RAPR协同工作，提出了一种新的射频导频辅助频偏估计(RAFOE)算法，通过搜索频谱样本的峰值可以轻松估计CFO。此外，为了在结合RAFOE和RAPR时以较低的计算成本获得最佳补偿性能，还提出了联合频偏和相位噪声补偿方案，并在475 Gbit/s偏振复用16进制正交幅度调制相干光正交频分复用（PM-16QAM-CO-OFDM）系统中对其性能进行了数值验证。
The vulnerable sensitivity to laser linewidth induced inter-carrier interference (ICI) has long been recognized as a major problem to coherent optical orthogonal frequency-division multiplexing (CO-OFDM) systems. Among the existing phase noise compensation algorithms, the RF-pilot aided phase recovery (RAPR) method shows a better compensation capability to laser linewidth. However, RAPR may fail to extract the pre-inserted RF-pilot at the receiver due to the influence of carrier frequency offset (CFO). An effective frequency offset estimation (FOE) is thus required to implement before performing RAPR. In consideration of the fact that the conventional FOE algorithm not only has high computational complexity, but more importantly cannot work in coordination with RAPR, a new RF-pilot aided frequency offset estimation (RAFOE) algorithm is proposed, in which CFO can be easily estimated by searching the peak of spectral samples. Furthermore, in order to obtain the optimum compensation performance with lower computing cost at combining RAFOE and RAPR, a joint frequency offset and phase noise compensation scheme is also proposed, and its performance is numerically verified in a 475 Gbit/s polarization multiplexed 16-ary quadrature amplitude modulation coherent optical orthogonal frequency-division multiplexing (PM-16QAM- CO-OFDM) system.