To improve the spectral efficiency of a full spectrum modulated nonlinear frequency division multiplexing (FS-NFDM) system, a blind frequency offset estimation (FOE) method has been proposed. The approach based on the minimum phase correction error can achieve high estimation accuracy of sub-MHz without need of any training symbols. Furthermore, in order to reduce the computational complexity, an eigenvalue-shift method is used to get a coarse search interval of FO, and then the one-dimensional optimization algorithm based on golden section search and parabolic interpolation is used to get the optimal FOE for the coarse search interval. The feasibility and reliability of the proposed blind FOE approach have been demonstrated in both BTB and fiber transmission scenarios. Compared with the grid search method, the proposed solving scheme can save hundreds of times of the searches. The experimental results reveal that the proposed method is robust to the amplified spontaneous emission noise and phase noise and has the capabilities of a wide FOE range and a high FOE accuracy.

中文翻译：

---

全频谱调制NFDM系统基于最小相位校正误差的盲频偏估计方法

为了提高全频谱调制非线性频分复用（FS-NFDM）系统的频谱效率，提出了盲频偏估计（FOE）方法。基于最小相位校正误差的方法无需任何训练符号即可实现sub-MHz的高估计精度。此外，为了降低计算复杂度，采用特征值平移方法得到FO的粗搜索区间，然后利用基于黄金分割搜索和抛物线插值的一维优化算法得到最优FOE粗搜索间隔。所提出的盲 FOE 方法的可行性和可靠性已在 BTB 和光纤传输场景中得到证明。与网格搜索方法相比，所提出的求解方案可以节省数百次搜索次数。实验结果表明，该方法对放大的自发辐射噪声和相位噪声具有鲁棒性，并且具有宽FOE范围和高FOE精度的能力。