非线性高斯噪声模型的再研究：混合光纤跨距的情况
Revisiting the nonlinear Gaussian noise model: The case of hybrid fiber spans
摘要：
我们从第一性原理重新推导，并将非线性高斯噪声模型的理论框架推广到每个跨度具有多个光纤类型和理想奈奎斯特光谱的相干光学系统的情况。我们专注于混合光纤跨距的非线性噪声方差的积分的精确数值评估。这项任务包括解决四个计算方面：（i）采用一种新的变量变换（除了使用双曲线坐标），改变被积函数的数值积分更合适的形式;（ii）分析评估的积分在其下限，其中被积函数提出了一个奇点;（iii）将积分区间划分为大小为pi的子区间，并通过使用各种算法来近似每个子区间中的积分;以及（iv）当积分区间被截断以加速计算时，导出相对误差的上界。我们将该模型应用于具有准单模光纤和单模光纤段组成的混合光纤跨距的相干光通信系统。采用分步傅里叶方法和蒙特卡罗模拟方法，对混合光纤跨距长距离相干光通信系统中非线性噪声方差的最终解析关系式的准确性进行了检验。它被证明是足够的，在0.1 dBQ的最佳光纤段长度的确定，最大限度地提高系统性能。
英文摘要：
We rederive from first principles and generalize the theoretical framework of the nonlinear Gaussian noise model to the case of coherent optical systems with multiple fiber types per span and ideal Nyquist spectra. We focus on the accurate numerical evaluation of the integral for the nonlinear noise variance for hybrid fiber spans. This task consists in addressing four computational aspects: (i) Adopting a novel transformation of variables (other than using hyperbolic coordinates) that changes the integrand to a more appropriate form for numerical quadrature; (ii) Evaluating analytically the integral at its lower limit, where the integrand presents a singularity; (iii) Dividing the interval of integration into subintervals of size pi and approximating the integral in each subinterval by using various algorithms; and (iv) Deriving an upper bound for the relative error when the interval of integration is truncated in order to accelerate computation. We apply the proposed model to coherent optical communications systems with hybrid fiber spans composed of quasi-singlemode fiber and single-mode fiber segments. The accuracy of the final analytical relationship for the nonlinear noise variance in long-haul coherent optical communications systems with hybrid fiber spans is checked using the split-step Fourier method and Monte Carlo simulation. It is shown to be adequate to within 0.1 dBQ for the determination of the optimal fiber segment lengths per span that maximize system performance.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
