当前位置: X-MOL 学术J. Lightw. Technol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Adaptive Turbo Equalization for Nonlinearity Compensation in WDM Systems
Journal of Lightwave Technology ( IF 4.7 ) Pub Date : 2021-09-13 , DOI: 10.1109/jlt.2021.3111095
Edson Portodasilva , Metodi Plamenov Yankov

In this paper, the performance of adaptive turbo equalization for nonlinearity compensation (NLC) is investigated. A turbo equalization scheme is proposed where a recursive least-squares (RLS) algorithm is used as an adaptive channel estimator to track the time-varying intersymbol interference (ISI) coefficients associated with inter-channel nonlinear interference (NLI) model. The estimated channel coefficients are used by a MIMO $2\times 2$ soft-input soft-output (SISO) linear minimum mean square error (LMMSE) equalizer to compensate for the time-varying ISI. The SISO LMMSE equalizer and the SISO forward error correction (FEC) decoder exchange extrinsic information in every turbo iteration, allowing the receiver to improve the performance of the channel estimation and the equalization, achieving lower bit-error-rate (BER) values. The proposed scheme is investigated for polarization multiplexed 64QAM and 256QAM, although it applies to any proper modulation format. Extensive numerical results are presented. It is shown that the scheme allows up to 0.7 dB extra gain in effectively received signal-to-noise ratio (SNR) and up to 0.2 bits/symbol/pol in generalized mutual information (GMI), on top of the gain provided by single-channel digital backpropagation.

中文翻译:

WDM系统中非线性补偿的自适应涡轮均衡

在本文中,研究了用于非线性补偿 (NLC) 的自适应涡轮均衡的性能。提出了一种涡轮均衡方案,其中递归最小二乘 (RLS) 算法用作自适应信道估计器,以跟踪与信道间非线性干扰 (NLI) 模型相关联的时变符号间干扰 (ISI) 系数。估计的信道系数由 MIMO 使用$2\乘以 2$软输入软输出 (SISO) 线性最小均方误差 (LMMSE) 均衡器,以补偿时变 ISI。SISO LMMSE 均衡器和 SISO 前向纠错 (FEC) 解码器在每次 turbo 迭代中交换外在信息,使接收器能够提高信道估计和均衡的性能,从而实现较低的误码率 (BER) 值。所提出的方案是针对极化复用的 64QAM 和 256QAM 进行研究的,尽管它适用于任何适当的调制格式。提供了广泛的数值结果。结果表明,该方案在有效接收信噪比 (SNR) 中允许高达 0.7 dB 的额外增益,在广义互信息 (GMI) 中允许高达 0.2 比特/符号/pol,除了由单个-通道数字反向传播。
更新日期:2021-11-12
down
wechat
bug