CAJ | 학술논문

传统的16 QAM(16进制正交幅度调制)相干光系统的相位估计算法主要采用 QPSK(正交相移键控)分圈法，然而受放大器 ASE(自发辐射)噪声的影响，星座点的径向移动将对相位恢复的准确度造成严重影响。文章针对星座点受噪声影响程度的不同，对 QPSK分圈法中的分类幅值阈值进行详细分析，并引入不同权重。蒙特卡罗仿真结果表明，该改进方法不仅能有效提高16 QAM的相位恢复精度，而且具有更低的误码率。
전통적16 QAM(16진제정교폭도조제)상간광계통적상위고계산법주요채용 QPSK(정교상이건공)분권법，연이수방대기 ASE(자발복사)조성적영향，성좌점적경향이동장대상위회복적준학도조성엄중영향。문장침대성좌점수조성영향정도적불동，대 QPSK분권법중적분류폭치역치진행상세분석，병인입불동권중。몽특잡라방진결과표명，해개진방법불부능유효제고16 QAM적상위회복정도，이차구유경저적오마솔。
The traditional 1 6 QAM phase estimation algorithm for coherent optical systems chiefly employs QPSK partitioning. However,owing to the influence of amplifier ASE noise,the radial movement of the constellation point seriously affects the ac-curacy of the phase recovery.In view of the different extent of the effects,this paper makes a detailed analysis of the classified amplitude threshold in the QPSK partitioning and proposes an analytical model that takes the relationship of Optical SNR (OS-NR),the length of summing window,and the threshold radius into account.The model also induces a group of weighted coef-ficients into phase estimation.Monte Carlo simulation results show that the improved method effectively increases the precision of phase recovery with still lower BER.