采用APD检测的编码瑞利BOTDA系统性能

发布时间：2019-07-15 08:52

【摘要】：瑞利布里渊光时域分析系统具有单光源、单端工作、非破坏的优点,为了解决系统信噪比与空间分辨率之间的矛盾,将编码技术应用到瑞利布里渊光时域分析系统中,可以在保持空间分辨率不变的前提下提高系统信噪比。提出了基于雪崩光电二极管检测和Simplex编码的瑞利布里渊光时域分析系统,系统中的随机散粒噪声功率和信号功率有关,而热噪声功率主要取决于雪崩光电二极管光电检测器的性能、与信号功率无关。由系统中与两种噪声相关的电流波动的方差和Simplex码的编解码规则可得编码系统的均方误差,由此推导了系统信噪比和编码增益公式。随着编码长度的增加,编码增益会逐渐增大并在某一编码长度后趋于稳定,因此系统存在最佳编码长度,最终推导了最佳编码长度公式,并对信噪比和最佳编码长度进行了MATLAB仿真。仿真结果表明,在基于Simplex码的瑞利布里渊光时域分析系统中,当脉冲基底1阶边带产生的瑞利散射光功率为0.5mW时,随编码长度的增加,编码增益逐渐增大并趋于稳定值6.69 dB,系统的最佳编码长度为63 bit。
[Abstract]:The Rayleigh Brillouin optical time domain analysis system has the advantages of single light source, single terminal operation and non-destructive. In order to solve the contradiction between the signal to noise ratio and the spatial resolution of the system, the coding technology is applied to the Rayleigh Brillouin optical time domain analysis system, which can improve the signal to noise ratio of the system while keeping the spatial resolution unchanged. A Riley Brillouin optical time domain analysis system based on avalanche photodiode detection and Simplex coding is proposed. The random particle noise power in the system is related to the signal power, and the thermal noise power mainly depends on the performance of the avalanche photodiode photodetector and is independent of the signal power. The mean square error of the coding system can be obtained from the variance of current fluctuation related to two kinds of noise and the coding and decoding rules of Simplex code, and the formulas of signal-to-noise ratio (SNR) and coding gain of the system are derived. With the increase of coding length, the coding gain increases gradually and tends to be stable after a certain coding length, so the system has the optimal coding length. Finally, the formula of the optimal coding length is derived, and the signal-to-noise ratio (SNR) and the optimal coding length are simulated by MATLAB. The simulation results show that when the Rayleigh scattering light power generated by the first order sideband of the pulse substrate is 0.5mW, the coding gain increases gradually with the increase of the coding length and tends to be stable at 63 bit. in the Reilly Brillouin optical time domain analysis system based on Simplex code.
【作者单位】：华北电力大学电子与通信工程系;
【基金】：河北省自然科学基金(F2014502098) 国家自然科学基金(61377088) 中央高校基本科研业务费专项资金(2016XS104)
【分类号】：TP212

【相似文献】