CAJ | 학술논문

鉴于相干光正交频分复用系统（CO‐OFDM ）易受非线性效应影响，严重制约系统传输性能，提出一种基于星座恢复的降低系统峰均值功率比（PAPR）的方法。对系统模型及作用机理进行分析，仿真结果显示，以10 Gbit／s的速率通过单模光纤传输720 km ，基于星座恢复的CO‐OFDM 系统Q值较无非线性抑制的CO‐OFDM 系统有3 dB提高；另外，系统最佳限幅比例系数受色度色散影响，随着色散因子的增大，星座恢复效果也逐渐减弱，在传输240 km条件下，色散因子为12 ps／nm · km较6 ps／nm · km ，限幅比例系数从0．9降低至0．8。
감우상간광정교빈분복용계통（CO‐OFDM ）역수비선성효응영향，엄중제약계통전수성능，제출일충기우성좌회복적강저계통봉균치공솔비（PAPR）적방법。대계통모형급작용궤리진행분석，방진결과현시，이10 Gbit／s적속솔통과단모광섬전수720 km ，기우성좌회복적CO‐OFDM 계통Q치교무비선성억제적CO‐OFDM 계통유3 dB제고；령외，계통최가한폭비례계수수색도색산영향，수착색산인자적증대，성좌회복효과야축점감약，재전수240 km조건하，색산인자위12 ps／nm · km교6 ps／nm · km ，한폭비례계수종0．9강저지0．8。
Coherent optical orthogonal frequency division multiplexing (CO‐OFDM ) system is sensitive to nonlinearity because of high peak‐to‐average power ratio (PAPR) and closely‐packed subcarriers ,w hich seriously suppresses the transmission performance .A method for re‐ducing the PAPR was put forward based on constellation restoration ,the system model and ac‐tion mechanism were analyzed .Analyses and simulation results show that ,the system Q value of constellation restoration based CO‐OFDM system is improved by about 3 dB for 720 km dis‐tance at a speed of 10 Gbit/s transmission through standard‐single‐mode fiber (SSM F ) ,com‐pared with the CO‐OFDM system without nonlinearity suppression .Meanwhile ,the clipping factor is strongly influenced by the chromatic dispersion w hich can decrease the effect of con‐stellation restoration .At the length of 240 km ,the clipping factor is 0 .9 and 0 .8 ,while the dispersion factor is 12 ps/nm · km and 6 ps/nm · km ,respectively .