Geometric Shaping of 2-D Constellations in the Presence of Laser Phase Noise
Geometric Shaping of 2-D Constellations in the Presence of Laser Phase Noise
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DOI：
10.1109/jlt.2020.3031017
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发表时间：
2020-07
影响因子：
4.7
通讯作者：
Hubert Dzieciol;G. Liga;E. Sillekens;P. Bayvel;D. Lavery
中科院分区：
文献类型：
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作者：
Hubert Dzieciol;G. Liga;E. Sillekens;P. Bayvel;D. Lavery
在本文中，我们提出了一种几何整形（GS）策略来设计受加性高斯白噪声（AWGN）和相位噪声损害的光纤信道的8、16、32和64位调制格式。使用不匹配的信道模型优化星座以最大化广义互信息（GMI）。与正交调幅（QAM）或awgn优化的对应物相比，所提出的格式在高相位噪声条件下具有增强的信噪比（SNR）容忍度。通过将优化结果置于400ZR实施协议的背景下，我们表明GS单独可以放松400 Gbit/s传输链路的激光线宽（LW）或载波相位估计（CPE）要求。在GMI验证之后，根据软判决（SD）扩展汉明码（122,120）的后发纠错（FEC）误码率（BER）来检查所呈现格式的性能，按照400ZR实现协议实现。与64位AWGN形格式相比，我们展示了高达1.2 dB的增益。
In this article, we propose a geometric shaping (GS) strategy to design 8, 16, 32, and 64-ary modulation formats for the optical fibre channel impaired by both additive white Gaussian (AWGN) and phase noise. The constellations were optimised to maximise generalised mutual information (GMI) using a mismatched channel model. The presented formats demonstrate an enhanced signal-to-noise ratio (SNR) tolerance in high phase noise regimes when compared with their quadrature amplitude modulation (QAM) or AWGN-optimised counterparts. By putting the optimisation results in the context of the 400ZR implementation agreement, we show that GS alone can either relax the laser linewidth (LW) or carrier phase estimation (CPE) requirements of 400 Gbit/s transmission links and beyond. Following the GMI validation, the performance of the presented formats was examined in terms of post forward error correction (FEC) bit-error-rate (BER) for a soft decision (SD) extended Hamming code (128, 120), implemented as per the 400ZR implementation agreement. We demonstrate gains of up to 1.2 dB when compared to the 64-ary AWGN shaped formats.