基于LMS算法的光纤振动预警系统降噪技术研究

Research on Noise Control Technology in Optical-fiber Vibration Early-warning System Based on LMS Algorithm

采用干涉光相位调制的光纤振动预警系统灵敏度极高,其信道易受随环境时变加性噪声污染而导致系统漏报误报与定位精度降低。通过建立基于马赫曾德干涉仪的系统结构,分析振动信号在光纤中的调制模型,采用基于LMS算法与HLMS算法的自适应噪声抵消器进行系统信号降噪。经过算法理论推导与Matlab环境仿真,结果表明,该降噪方案能有效还原受时变确定噪声以及随机噪声污染的信号,稳态均方误差值不高于0.1,且算法简单高效,收敛速度快,具有工程应用价值。

The channel of optical-fiber vibration early-warning system using interferometric phase modulation with the character of high sensitivity can easily be polluted by additive noise with environment change so that the false alert or missed alert may arise. On the basis of the system structure based on Mach-Zehnder interferomete and the analysis of vibration signal modulation,an adaptive noise canceller based on LMS algorithm and HLMS algorithm is used to control system noise. The theoretical derivation and simulation result in Matlab showed that this noise reduction scheme can restore the signal which is polluted by random noise or certain noise accurately and steady state square error of it is below 0.1. In the meantime,the algorithm is fit in with engineering applications because it is simple and fast.