利用Optisystem仿真软件搭建了基于DQPSK(差分正交相移键控)编码的WDM(波分复用)单纤双向传输系统, 实现系统传输扩容; 同时提出采用分段色散补偿方法抑制色散对系统的影响, 利用非均匀信道间隔设置和非均匀色散管理降低四波混频效应。结果表明: 在传输距离为600 km、单信道速率为40 Gbit/s的8信道WDM系统中, 单纤双向传输时系统的品质因子(Q值)比单纤单向传输系统最大提高了14.9 dB; 对系统进行色散和四波混频抑制后, 系统Q值还可以提高11 dB以上。

This paper sets up a simulation model by using the Optisystem for a DQPSK modulation-based single-fiber bidirectional WDM transmission system for performing system capacity expansion, inhibiting the effects of dispersion on the system by step dispersion compensation and reducing the FWM effects by non-uniform channel interval setting and non-uniform dispersion management. The results indicate that when the transmission distance of an 8-channel 40 Gbit/s WDM transmission system is 600 km, the Q factor of a single-fiber bidirectional transmission is improved by 14.9 dB to the maximum compared with a single-fiber unidirectional transmission system. Furthermore, when the dispersion and FWM effects are inhibited, the system Q factor can be improved by over 11 dB.