光纤水听器系统光纤传输噪声的自适应消除

传输光纤引入的偏振和相位调制噪声给光纤水听器远程传输系统带来严重影响.论文提出使用一个声压和加速度不灵敏的参考探头来获取传输光纤引入的公共噪声,并将该噪声进行自适应滤波处理来估计和消除传感探头中传输噪声的方案.实验结果表明,归一化最小均方误差(NLMS)自适应算法对冲击传输光纤引入的宽带偏振噪声抑制最大达20 dB;对传输光纤中大幅度的单频连续相位调制噪声抑制达20 dB;自适应滤波基本消除了传输噪声的影响,并且完整保留了传感探头中的仿真信号.实验同时证明,自适应噪声消除的结果优于直接将参考探头与传感探头信号相减的噪声抑制效果.

Adaptive Elimination of Lead Fiber Induced Noise in an Optical Fiber Hydrophone System

Polarization and phase modulation noises caused by the lead fiber are harmful to a long-haul fiber hydrophone system. In this paper we used a pressure and acceleration insensitive reference hydrophone to obtain the lead fiber induced common noise, and then used adaptive noise cancellation to remove them from a primary hydrophone. Experimental results show that by the use of Normalized Least-mean-square (NLMS) algorithm, a broadband polarization noise caused by disturbing the lead fiber is suppressed by maximal 20 dB and a narrowband phase modulation noise is suppressed by 20 dB. Thus the lead fiber induced noise is eliminated and no reduction in the amplitude of the simulated signal is found. It is shown that the results of adaptive noise cancellation are much better than that of the noise subtract method.