八进制调制DWDM系统非线性效应仿真研究

J4 ›› 2017, Vol. 34 ›› Issue (6): 735-741.

八进制调制DWDM系统非线性效应仿真研究

杜建新¹,许悦²,滕之禹²

1. 南京邮电大学光电工程学院
2. 南京邮电大学

收稿日期:2016-08-25 修回日期:2016-10-30 出版日期:2017-11-28 发布日期:2017-12-11
通讯作者: 杜建新

Simulation Analysis of Nonlinear Effects for 8-ary Modulated DWDM System

Received:2016-08-25 Revised:2016-10-30 Published:2017-11-28 Online:2017-12-11

摘要/Abstract

摘要： 为了提高光纤通信系统频谱利用率，基于Optisystem软件搭建了2.88Tb/s (40-Gbaud/ch) 150GHz信道间隔的八进制调制密集波分复用（DWDM)系统。这里的八进制调制格式包括两种类型：八进制幅度差分相移键控（8APSK）和八进制差分相移键控（D8PSK）。仿真结果表明：当探测信道为8APSK，随着8APSK幅度调制指数的增大，最佳入射平均光功率明显变大。不管是8APSK还是D8PSK调制，当入射平均光功率为最佳取值时，四波混频噪声对系统性能的影响程度并不大，但当其超过最佳取值时，四波混频噪声随着入射平均光功率的增加对系统性能影响程度快速增加。对于我们所讨论的DWDM系统，幅度调制指数优化的8APSK信号传输性能明显要优于D8PSK，这主要归因于前者对总的非线性效应有更好的容忍度。

关键词: 八进制差分相移键控

Abstract: Based on the Optisystem platform, a 2.88Tb/s (40-Gbaud/ch) DWDM system with 150GHz channel spacing is built for high spectral efficiency fiber optical communication systems. The 8-ary modulation formats adopted here include two types. One of them is 8APSK (8-level amplitude- and differential phase-shift keying), the other is D8PSK (differential 8-level phase-shift keying). The simulation results show that when the probe channel is 8APSK modulated, larger amplitude modulation index corresponds to larger optimal input average optical power. When the input average optical power is optimal, the impact of four-wave mixing (FWM) noise on system performance is not strong whether the modulation format is 8APSK or D8PSK, but when it exceeds the optimal value, the impact increases abruptly with its value. 8APSK with optimized amplitude modulation index apparently outperforms D8PSK for our discussed DWDM system, as is mainly attributed to better tolerance of total nonlinearities for the former.

Key words: D8PSK

中图分类号:

TN929. 11

杜建新许悦滕之禹. 八进制调制DWDM系统非线性效应仿真研究[J]. J4, 2017, 34(6): 735-741.

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