基于FPGA的遮蔽条件下非线性畸变脉冲信号实时检测  

Real-time Ddetection of Nnonlinear Ddistorted Pulse Signal Under Masking Condition Based on FPGA

作　　者：陈云帆 梅竹青 李恒风 郑宇 孙中森 CHEN Yun-fan;MEI Zhu-qing;LI Heng-feng;ZHENG Yu;SUN Zhong-sen(College of Electronic Information,Qingdao University,Qingdao 266071,China)

机构地区：[1]青岛大学电子信息学院,山东青岛266071

出　　处：《中国电子科学研究院学报》2023年第10期903-911,共9页Journal of China Academy of Electronics and Information Technology

基　　金：国家重点研发计划战略性国际科技创新合作重点专项(2018YFE0206500)。

摘　　要：针对强脉冲信号在检测时导致自适应门限提升形成“遮蔽效应”影响弱信号检测的问题及强脉冲信号非线性畸变严重导致脉冲参数测量误差大的问题,提出一种非线性条件下自适应脉冲检测法,包括自适应门限与脉冲起止判决法两部分。其中自适应门限部分基于噪声分布特性提出平稳脉冲差分模型,对自适应门限进行改进降低“遮蔽效应”;脉冲起止判决部分采用最大差值判决法,在差分运算最大值处判决为脉冲的起止点,减小脉宽测量误差。经仿真验证及FPGA实测表明,改进后的自适应门限仅高于噪声约2 dB,“遮蔽效应”明显降低;在单信道51.2 MHz采样率的条件下,非线性畸变脉冲信号的脉宽平均测量误差由0.2μs减小至0.02μs。Aiming at the problem that the strong pulse signal causes the"masking effeact"to affect the weak signal detection and the nonlinear distortion of the strong pulse signal causes the large pulse parameter measurement error,an adaptive pulse detection method under nonlinear conditions is proposed,which includes the adaptive threshold and the pulse start-stop decision method.In the adaptive threshold part,a stationary pulse difference model is proposed based on the noise distribution characteristics,and the adaptive threshold is improved to reduce the"masking effect".In the part of pulse start-stop decision,the maximum difference decision method is adopted,and the pulse start and end point is determined at the maximum difference operation to reduce the pulse width measurement error.Simulation and FPGA measurement show that the improved adaptive threshold is only about 2 dB higher than the noise,and the"masking effect"is obviously reduced.Under the condition of single channel 51.2 MHz sampling rate,the average measurement error of nonlinear distorted pulse signal decreases from 0.2μs to 0.02μs.

关 键 词：非线性畸变 遮蔽效应 最大差值判决法 平稳脉冲差分模型 脉冲检测 

分 类 号：TN911.23[电子电信—通信与信息系统]