线路侧光模块CFP2-DCO在4G/5G网络建设中具有重要而广泛的应用, 而光信噪比(OSNR)指标是评估其性能的重要参数。对OSNR的不同测试方法进行了探讨, 并针对通信设备制造商在实验室对OSNR容限进行测试的需求, 提出了一种对CFP2-DCO的OSNR指标自动化测试的方法, 测试了发射端根升余弦(RRC)滤波器滚降(roll-off)系数的设置以及接收端载波相位恢复(CPR)窗口大小的设置对OSNR的代价, 并结合实际对roll-off和CPR窗口大小的选择进行了分析。测试结果表明, 对于QPSK的几种调制模式, RRC的roll-off值的选取对OSNR的代价几乎可以忽略; 对于16QAM调制模式, RRC的roll-off为0.5时, OSNR的代价最小; 对于8QAM调制模式, roll-off值为0.2时, OSNR代价最小; 对于Differential QPSK模式, 选用比较窄的8 symbols的窗口可以获得最好的性能。而对于相邻通道没有OOK调制和DCF的系统, non-differential算法可以起到好的效果。该测试方法对通信设备制造商的DWDM及ROADM系统性能测试及评估具有指导及借鉴意义。

The line side module CFP2-DCO has important and extensive application in 4G/5G network construct. OSNR is an important parameter to evaluate the performance of the CFP2-DCO. Different kinds of OSNR measurement methods are discussed in this paper. An OSNR automatic measurement method of the CFP2-DCO is introduced for the lab test requirement of communication?equipment?manufacturer. The penalty of the roll-off of the transmit filter and the receiver CPR window size are measured. The chosen of the roll-off coefficient and the CPR window size are analyzed. From the result, the OSNR penalty can almost be neglected with different roll-off value configuration of RRC for QPSK modulation modes. The OSNR penalty is the minimum when the roll-off value is 0.5 for 16QAM modulation mode. The OSNR penalty is the minimum when the roll-off value is 0.2 for 8QAM modulation mode. The narrower 8 symbols window size can achieve the best performance for differential QPSK mode. For systems without OOK modulation and DCF in adjacent channels, ?the non-differential algorithm can take good effect. The test method has guidance and reference significance for the DWDM and ROADM system performance test of the communication?equipment?manufacturer.