太赫兹光谱信号快速连续采集仿真研究

摘要

In this paper,we propose a method for rapid and continuous collection of terahertz spectral signal based on frequency domain sampling.Firstly,double-exponential vibration attenuation function with frequency-fixed signals interference was used to simulate local terahertz signal and phase position of Fourier transformation of the terahertz signal was reconstructed via bi-spectrum estimation.Then,time domain feature of the terahertz signal was acquired.Integrated with theorem of frequency domain sampling,constraint condition of interval of frequency sampling of the signal and time window was provided.Moreover,positions of large and small terahertz signals in the frequency domain were obtained,and location and maximum amplitude of strong signal were worked out.According to that,the rapid and continuous collection was finally,completed.The method has high collection precision and lays foundation for improving detection precision and rate of terahertz signal.%对太赫兹光谱信号的快速连续采集,可以提升太赫兹信号的检测精度与速率.对光谱信号进行采集,需要得到太赫兹大、小信号所处的位置,计算出强信号所处的位置和最大幅值,完成对信号的连续采集.传统方法先组建局部的太赫兹信号模型,对太赫兹信号进行估计,但忽略了计算出光谱强信号所处的位置和信号最大幅值,导致信号采集精度偏低.提出基于频域采样的太赫兹信号快速连续采集方法.以定频干扰的双指数振荡衰减函数来模拟局部太赫兹信号,通过双谱估计重构太赫兹信号Fourier变换的相位,获取太赫兹信号时域特征,融合于频域采样定理给出对太赫兹信号频率采样的间隔和时间窗长的约束条件,得到太赫兹大、小信号在频域所处的位置,计算出强信号所处的位置和最大幅值,以此为依据完成对太赫兹信号快速连续采集.实验结果表明,所提方法信号采集精度高,为提升对太赫兹信号的检测精度与速率奠定了基础.