分析了密集波分复用下的经典-量子信息共信道同传系统噪声特性,提出基于预报单光子源的经典-量子信息共信道同传方案.与传统的弱相干光源相比,其可以更精确地控制APD探测门限,进而实现时域滤波减少信道噪声干扰;并且可以通过控制探测器开启时间,有效避免空光子发送时的信道噪声及探测器暗计数影响。仿真结果表明,本方案提出的同传系统可有效抑制噪声干扰,与弱相干光源方案相比于更远距离达到误码率阈值,提升了安全通信距离,可作为远距离量子密钥通信共信道同传参考方案。
The typical noise in the multiplexed system based on dense wavelength division multiplexing(DWDM) was analyzed,and the scheme of multiplexed classical and quantum transmission system was proposed with a heralded single-photon source.Compared to weakly coherent pulses,the threshold-detection can be accurately controlled,and temporal-filtering can be achieved to reduce the noise jamming.On the other hand,the opening time of APD can be controled to avoid the noise and dark counts.The simulation results showed that the scheme of multiplexed classical and quantum transmission system can depress the impact of various noise,reaching the threshold of bit error rate at a farther distance compared to a weak coherent source.So the secure communication distance is increased in remote quantum key distribution communications.