BOTDR中散射谱中心频率的ESPRIT估计算法研究

摘要

在光纤布里渊光时域反射仪(BOTDR)系统中,对光纤中各处的布里渊散射谱中心频率的估计是测量的关键,也是最为费时的环节,导致BOTDR系统难以做到快速响应.本文研究了ESPRIT算法用来估计BOTDR系统中的布里渊散射谱中心频率,并与基于快速傅里叶变换(FFT)的频率估计算法进行了比较分析.结果表明,ESPRIT算法具有与补零FFT算法配合上洛伦兹频谱拟合所得结果相近的性能.由于ESPRIT算法对数据长度的要求较低,能够在短数据长度上获得较好的频率估计性能,因此能够在保证较高空间分辨率和测量性能的情况下,提高测量速度.%In fiber-optic Brillouin optical time-domain reflectometer (BOTDR) system, the estimation of the center frequency of Brillouin scattering spectrum in fiber is the key and the most time-consuming part of the measurement, which makes BOTDR system difficult to achieve fast response. In this paper, estimation of signal parameters via rotational invariance technique (ESPRIT) algorithm is proposed to estimate the center frequency of Brillouin scat-tering spectrum in BOTDR system. Due to fairly low requirement on data length, ESPRIT algorithm can obtain good frequency estimation over short data length, and makes it possible to increase measurement speed at high spatial resolution and measurement performance.