由于长距离光传输系统中常使用的线性复用技术,常将非线性视为一种干扰因素。非线性频分复用(Nonlinear Frequency Division Multiplexing,NFDM)近年来受到广泛关注,这种技术在非线性傅立叶域中对数据进行调制,被视为克服克尔非线性的...由于长距离光传输系统中常使用的线性复用技术,常将非线性视为一种干扰因素。非线性频分复用(Nonlinear Frequency Division Multiplexing,NFDM)近年来受到广泛关注,这种技术在非线性傅立叶域中对数据进行调制,被视为克服克尔非线性的一种潜在方法。本文详细介绍了相干光NFDM的理论推导和传输过程,并描述了b系数调制的概念和优化设计。在本文中,使用训练序列来实现基于b系数调制的NFDM系统的信道估计,并通过蒙特卡洛仿真进行验证。基于改进后的b系数调制方法相比于传统b系数调制方法具有更低的误码率并且可以传输更远的距离。此外,它的性能明显优于传统的调制反射系数的方法。展开更多
Strain-rate frequency superposition(SRFS) is often employed to probe the low-frequency behavior of soft solids under oscillatory shear in anticipated linear response. However, physical interpretation of an apparently ...Strain-rate frequency superposition(SRFS) is often employed to probe the low-frequency behavior of soft solids under oscillatory shear in anticipated linear response. However, physical interpretation of an apparently well-overlapped master curve generated by SRFS has to combine with nonlinear analysis techniques such as Fourier transform rheology and stress decomposition method. The benefit of SRFS is discarded when some inconsistencies of the shifted master curves with the canonical linear response are observed. In this work, instead of evaluating the SRFS in full master curves, two criteria were proposed to decompose the original SRFS data and to delete the bad experimental data. Application to Carabopol suspensions indicates that good master curves could be constructed based upon the modified data and the high-frequency deviations often observed in original SRFS master curves are eliminated. The modified SRFS data also enable a better quantitative description and the evaluation of the apparent structural relaxation time by the two-mode fractional Maxwell model.展开更多
文摘由于长距离光传输系统中常使用的线性复用技术,常将非线性视为一种干扰因素。非线性频分复用(Nonlinear Frequency Division Multiplexing,NFDM)近年来受到广泛关注,这种技术在非线性傅立叶域中对数据进行调制,被视为克服克尔非线性的一种潜在方法。本文详细介绍了相干光NFDM的理论推导和传输过程,并描述了b系数调制的概念和优化设计。在本文中,使用训练序列来实现基于b系数调制的NFDM系统的信道估计,并通过蒙特卡洛仿真进行验证。基于改进后的b系数调制方法相比于传统b系数调制方法具有更低的误码率并且可以传输更远的距离。此外,它的性能明显优于传统的调制反射系数的方法。
基金Project(11372263)supported by the National Natural Science Foundation of China
文摘Strain-rate frequency superposition(SRFS) is often employed to probe the low-frequency behavior of soft solids under oscillatory shear in anticipated linear response. However, physical interpretation of an apparently well-overlapped master curve generated by SRFS has to combine with nonlinear analysis techniques such as Fourier transform rheology and stress decomposition method. The benefit of SRFS is discarded when some inconsistencies of the shifted master curves with the canonical linear response are observed. In this work, instead of evaluating the SRFS in full master curves, two criteria were proposed to decompose the original SRFS data and to delete the bad experimental data. Application to Carabopol suspensions indicates that good master curves could be constructed based upon the modified data and the high-frequency deviations often observed in original SRFS master curves are eliminated. The modified SRFS data also enable a better quantitative description and the evaluation of the apparent structural relaxation time by the two-mode fractional Maxwell model.
