基于异构加速的Φ-OTDR实时信号处理系统

Real-Time Phase-Sensitive Optical Time-Domain Reflectometry Signal Processing System Based on Heterogeneous Accelerated Computing

针对相位敏感光时域反射计(Φ-OTDR)信号处理复杂、计算量大、实时性要求高的特点,提出一种基于现场可编程门阵列(FPGA)异构加速计算技术的Φ-OTDR实时信号处理系统。对外差探测式Φ-OTDR信号处理流程进行分析与分解,提出基于FPGA的滑动窗数据帧分割、多通道并行快速傅里叶变换(FFT)计算、频域滤波、短时能量求和等一系列加速计算方法。该系统最终实现在40 km光纤传感距离、2 kHz重复频率与1 m采样间隔下的长时间、实时扰动信号解调与显示,并且具有80%的帧重叠率。该FPGA系统作为异构加速器,能够减轻计算机数据处理压力,保证传感系统高重复频率下的运算实时性,为系统可靠性和稳定性提供了有效保障。

A real-time phase-sensitive optical time-domain reflectometry(Φ-OTDR)signal processing system is proposed based on the heterogeneous accelerated computing technology of field programmable gate array(FPGA)with respect to the characteristics of complexity,large-amount computation,and high real-time requirements of theΦ-OTDR signal processing system.Firstly,the heterodyne-detection-typeΦ-OTDR signal processing flow is analyzed and decomposed.Subsequently,a series of accelerated computing methods based on FPGA,such as sliding window data frame segmentation,multichannel parallel fast Fourier transform calculation,frequency-domain filtering,and short-term energy summation,are proposed.Finally,the system implements long and real-time disturbance signal demodulation and display using a fiber sensing distance of 40 km,a repetition rate of 2 kHz,and a sampling interval of 1 m with a frame overlap of 80%.The FPGA system acts as a heterogeneous accelerator to mitigate the computer data processing pressure and ensure real-time operation of the sensing system at a high repetition frequency,effectively ensuring the system reliability and stability.