Efficient Precoding Scheme for Dual-Polarization Multi-Soliton Spectral Amplitude Modulation
Efficient Precoding Scheme for Dual-Polarization Multi-Soliton Spectral Amplitude Modulation
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DOI：
10.1109/tcomm.2019.2935716
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发表时间：
2019-11-01
影响因子：
8.3
通讯作者：
ten Brink, Stephan
中科院分区：
文献类型：
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作者：
Span, Alexander;Aref, Vahid;ten Brink, Stephan
在光纤通信中，孤子脉冲是一种特殊的非线性波形。它们可以用沿理想连杆的简单变换方程的特征值和谱幅在非线性谱中表示。这促使人们对非线性频谱中的数据进行编码。在本文中，我们考虑了频谱振幅的双偏振调制，并表明它们在沿有噪声光纤链路传播时变得高度相关。因此，通常需要联合均衡来进行接收端的检测。我们提出了一个简单的预编码方案，几乎消除了这些相关性。这允许显着提高检测性能，即使没有任何复杂的均衡。将谱幅值变换成公信息部分和微分信息部分。我们表明，即使在存在噪声的情况下，微分部分也几乎沿着链路保持不变。因此，可以直接从接收到的光谱幅值进行检测，可靠性高。利用预编码的差分增益可以在相当的错误率下实现更高的比特率。我们分析了我们的预编码方案，并通过将其与传统的一阶和二阶孤子的谱幅独立调制进行比较，验证了其在分步傅里叶模拟中的性能增益。
Soliton pulses are special waveforms to account for nonlinearity in fiber optical communication. They can be represented in a nonlinear spectrum by eigenvalues and spectral amplitudes which have simple transformation equations along the ideal link. This motivates to encode data in the nonlinear spectrum. In this paper, we consider dual-polarization modulation of spectral amplitudes, and show that they become highly correlated during propagation along a noisy fiber link. Thus, joint equalization is generally needed for detection at the receiver. We propose a simple precoding scheme that almost removes these correlations. This allows to significantly improve the detection performance even without any complex equalization. The spectral amplitudes are transformed into pairs of common and differential information part. We show that the differential part is almost preserved along the link, even in the presence of noise. Thus, it can be directly detected from the received spectral amplitudes with high reliability. Exploiting the differential gain of the precoding allows much higher bit rates at comparable error rates. We analyze our precoding scheme and verify its performance gain in split-step-Fourier simulations by comparing it to the conventional independent modulation of spectral amplitudes for first and second order solitons.