差分相移键控色散管理孤子多扰动系统的相位抖动

Phase Jitter of Multi-Perturbations in Differential Phase-Shift Keying Dispersion Managed Soliton System

差分相移键控（DPSK）调制方式和色散管理孤子传输方式的结合能抵制噪声和非线性损伤，在高速（40Gbit／s以上）多信道系统中具有突出的优点。采用变分法分析了多波长信道的放大自发辐射（ASE）噪声、信号间的非线性串扰（ISI）等多种扰动因素引起差分相移键控色散管理孤子系统的均方根相位抖动，给出了扰动的作用区域以及各扰动的大小。研究发现，放大自发辐射引起的抖动与传输距离成三次方的关系，而交叉相位调制（XPM）引起的抖动与距离近似成线性关系。通过优化选择色散管理图强度范围1．5～3．5，各种扰动得到了抑制，而以放大自发辐射扰动抑制为最大，此时要远低于交叉相位调制引起的抖动，然后分别是交叉相位调制一放大自发辐射扰动和交叉相位调制，从而波分复用系统主要来自于增加信道数这一客观限制。

A combination of differential phase-shift keying （DPSK） modulation format with dispersion managed soliton （DMS） transmission technique can depress the noise and nonlinear damage, and gives additional innovative advantage in densely spaced channels at high bit rates （40 Gbit/s and more） systems. The phase jitter of root of mean square induced by multi-perturbations is analyzed by variational method in differential phase-shift keying dispersion managed solition system, which includes the amplifier spontaneous emission （ASE） noise, intra-symbol interference （ISI） between the channels. The effect area and magnitudes of multi-perturbations are given. The results declare that phase jitter induced by amplifier spontaneous emission noise is almost cubic relationship with transmission distance and phase jitter induced by cross phase modulation （XPM） is nearly linear with transmission distance. With the optimal dispersion management map strength S from 1.5 to 3.5, the perturbations are restrained. The phase jitter of amplifier spontaneous emission noise which is far below XPM＇s now is most decreased than the XPM-ASE and XPM. Then wave division multiplexing system is restricted by the external factor of the channel numbers increasing.