基于相关序列脉冲的布里渊光时域反射测量系统解码方法研究  

Study on Decoding Method of Correlation Coded Pulses Based Brillouin Optical Time-Domain Reflectometric System

作　　者：梁浩[1] 路元刚[1] 李存磊[1] 王祥传[1] 张旭苹[1] 

机构地区：[1]南京大学光通信工程研究中心,江苏南京210093

出　　处：《光学学报》2011年第10期69-74,共6页Acta Optica Sinica

基　　金：国家自然科学基金(61027017;60644001);国家973计划(2010CB327803)资助课题

摘　　要：布里渊光时域反射测量(BOTDR)系统空间分辨率和传感距离存在相互制约的关系。相关序列脉冲编码技术可用于解决这一矛盾,但直接对编码脉冲的布里渊散射采样信号进行解码,会因采样时间间隔小于编码单位脉冲宽度而导致解码信号的失真,从而降低了系统空间分辨率和测量精度。分析了直接互相关解码对BOTDR系统空间分辨率的影响,提出一种基于重采样的互相关解码方法,该方法解决了直接相关运算造成的系统性能降低问题。实验中用512bit 20ns的互补序列在20km光纤末端获得2m的空间分辨率。实验结果表明,与直接互相关的解码方法相比,基于重采样的互相关方法是一种有效的序列脉冲BOTDR信号解码方法。There is a trade-off between spatial resolution and sensing range of conventional Brillouin optical time domain reflectometry（BOTDR） system.Correlation coded pulses encoding technique has been used to solve this problem.However,when the sampling duration is smaller than the unit pulse width,the restored traces might be distorted by using direct correlation decoded method,thus it will decrease the spatial resolution and accuracy of the system.The influence of the direct correlation based decoded method on the spatial resolution of the system is studied,and a re-sampling based correlation technique is proposed to solve the problem introduced by the direct correlation method.2 m spatial resolution is achieved over 20 km fiber by using 512 bit 20 ns Golay complementary codes and the new decoded method.The experimental result shows that the proposed decoding method is an effective technique for data processing of coded pulse based BOTDR system.

关 键 词：光纤传感 布里渊光时域反射 相关序列 编码脉冲 采样率 

分 类 号：TN247[电子电信—物理电子学]