经典-量子信息共信道同传是光纤量子密钥通信中的关键应用技术。为解决同传系统在复杂的背景噪声环境下的传输效率问题, 通过剖析基于DWDM的共信道同传系统中典型噪声干扰因素, 对该系统中DWDM信道串扰及自发拉曼散射噪声建立模型, 仿真计算不同光纤长度及不同波长信道下噪声干扰对系统的影响。分析结果表明, 在初始功率恒定的情况下, 系统噪声不会随光纤长度增加而无限积累, 而是趋于恒定数值；而在接收功率恒定的情况下, 系统噪声随光纤长度增加不断增长。从信道的波长角度看, 处于低噪声环境的经典与量子信道波长符合密集波分复用要求。根据ITU-T建议下的DWDM信道间隔, 在经典-量子信道波长间距为1.6 nm时, 系统性能最佳, 该仿真结果与经典实验的结论相吻合。

The multiplexed classical and quantum transmission was one of the key application technologies of quantum key communications.To solve the problem of transmission efficiency in complex background system, this text analyzed the typical noise in the multiplexed system based on DWDM, modeling the DWDM crosstalk and the spontaneous raman scattering in the system, simulating calculation for the noise influence in different fiber lengths and different channel wavelengths.The analysis showed that, system noise did not accumulate indefinitely with the growth of the fiber lengths but went to a steady value in the case of initial power constant.However, it was on the rise with the growth of the fiber lengths in the case of received power constant.From the channel wavelength of view, the classical and quantum channel wavelength in low noise environment was accorded with the demand of the Dense Wavelength Division Multiplexing.Based on the suggestion of channel spacing by ITU-T, the best system performance was for 1.6 nm classical-quantum channel spacing which was in accordance with the conclusion of classical experiments.