SαS分布噪声模型下激光信号互相关时延估计  

Time delay estimation of laser signal cross correlation based on SαS distributed noise model

作　　者：李丰君 徐广平 耿林 霍晓培 LI Feng-jun;XU Guang-ping;GENG Lin;HUO Xiao-pei(North China Research Institute of Electro-Optics,Beijing 100015,China)

机构地区：[1]华北光技术研究所,北京100015

出　　处：《激光与红外》2022年第12期1781-1786,共6页Laser & Infrared

摘　　要：高斯噪声模型因其能够避免非线性问题且易于工程实现在早期多被采用,然而在实际应用中,往往存在脉冲幅度特性的噪声和干扰。因此本文对非高斯噪声背景下脉冲式激光测距互相关时延估计算法进行了研究。首先采用钟形脉冲模型对发射激光脉冲进行建模、采用SαS(Symmetric Alpha-Stable)模型对脉冲噪声进行建模;然后提出了基于Sigmoid函数的互相关时延估计算法,通过检测互相关峰值位置就可以得到回波信号相对于发射激光脉冲的时延;最后对Sigmoid函数中的k值进行分析,通过大量仿真,在发射激光脉冲宽度一定时,激光脉冲幅值A与k的关系为kA≈3时,■最小,时延估计效果最好。该方法时延估计效果与直接使用k=1的时延估计效果对比,有明显提升。Gaussian noise model is widely used in the early stage due to its ability to avoid non-linearity and ease of engineering implementation, however, in practice, there is often noise and interference in the pulse amplitude characteristics.In this paper, the cross-correlation time delay estimation algorithm for pulse laser ranging in the context of non-Gaussian noise is studied.Firstly, a bell-shaped pulse model is used to model the emitted laser pulse and SαS(Symmetric Alpha-Stable) model is used to model impulse noise;then a cross-correlation time delay estimation algorithm based on Sigmoid function is proposed to obtain the time delay of the echo signal relative to the emitted laser pulse by detecting the location of the cross-correlation peak;finally, the value of K in Sigmoid function is analyzed, and through a large number of simulations, when the laser pulse width is certain, the relationship between the laser pulse amplitude A and K is KA ≈ 3,is the minimum, the effect of time delay estimation is the best.The delay estimation results of this method are significantly improved compared with that of k=1.

关 键 词：脉冲式激光测距 非高斯背景 SIGMOID函数 互相关 

分 类 号：TN242[电子电信—物理电子学]