基于雷达信号的脉内分析及目标检测技术研究

发布时间：2018-06-15 01:23

本文选题：调制方式识别 + 脉冲描述字　；参考：《电子科技大学》2017年硕士论文

【摘要】：对雷达信号进行脉内分析和目标检测是雷达系统的两个重要功能,同时也是其后续信号分析处理工作的技术基础。为进一步提升雷达系统的性能,降低雷达信号后续分析处理的难度,论文开展了基于雷达信号的脉内分析及目标检测技术研究,在有效识别雷达信号调制方式的基础上,着重研究了脉冲描述字中到达时间和载频的估计问题,详细设计了脉内分析和目标检测的实现流程,以研制的雷达信号接收机处理系统软件为依托充分进行了仿真实验分析。论文的主要研究成果和结论如下:1.研究了雷达信号调制方式识别的问题。在分析了调频FM信号中的LFM信号和NLFM信号与相位编码PSK信号中的BPSK信号和QPSK信号的基础上,采用基于信号3dB带宽的方法实现对FM和PSK两类信号的区分,提出采用基于小波脊线的方法分别实现这两类信号的类内细分。仿真实验表明,当信噪比SNR大于3dB时,FM信号和PSK信号的类间识别正确率达到90%以上;当SNR大于0dB时,FM信号类内细分的正确率和PSK信号类内细分的正确率都稳定在100%。2.重点研究了脉冲达到时间和载频等雷达信号脉内参数的估计问题。针对脉冲到达时间,提出了一种基于三角小波的高精度估计方法,该方法同时适用于常规矩形包络信号、LFM信号和PSK信号,仿真结果表明该方法相对于参考小波对脉冲到达时间的估计精度提高了至少20%以上。针对LFM信号的载频估计问题,提出了一种DPT+FRFT二维插值算法,仿真结果表明该算法在缩短50%计算时长的情况下依然保持了较小的相对误差;针对PSK信号的载频提出了一种基于小波脊线结合自适应MAT的估计方法,仿真结果表明当SNR在4d B左右时该算法的载频相对误差可达到60ppm以下。3.在调制方式识别和脉内参数估计研究的基础上,开展了基于外辐射源雷达信号的脉内分析和目标检测的技术开发和仿真实验。实现了外辐射源雷达信号接收机系统的总体设计,详细设计了脉内分析子系统和目标检测子系统的实现流程,编制了外辐射源信号处理接收机系统仿真软件,并进行了各种仿真实验。结果显示脉内分析子系统和目标检测子系统都达到了预期的目标,符合工程应用要求,最终实现了对目标的精确检测,表明了所提出的方法和系统方案是合理的,具有较高的工程应用价值。
[Abstract]:The in-pulse analysis and target detection of radar signal are two important functions of radar system, and are also the technical basis of its subsequent signal analysis and processing. In order to further improve the performance of radar system and reduce the difficulty of subsequent analysis and processing of radar signal, the research of in-pulse analysis and target detection technology based on radar signal is carried out in this paper, and the modulation mode of radar signal is recognized effectively. In this paper, the estimation of arrival time and carrier frequency in pulse descriptor is studied, and the realization flow of intra pulse analysis and target detection is designed in detail. Based on the developed software of radar signal receiver processing system, the simulation experiment is carried out. The main research results and conclusions are as follows: 1. The problem of radar signal modulation recognition is studied. Based on the analysis of LFM signal and NLFM signal in FM signal and BPSK signal and QPSK signal in phase-coded PSK signal, the method based on 3dB bandwidth is used to distinguish FM and PSK signals. A method based on wavelet ridge is proposed to realize the subdivision of the two kinds of signals. The simulation results show that the inter-class recognition accuracy of FM signal and PSK signal is more than 90% when SNR is greater than 3dB, and the accuracy rate of intra-class subdivision of FM signal and subdivision of PSK signal is stable at 100 / 02 when SNR is greater than 0 dB. The estimation of the pulse parameters of radar signals, such as pulse arrival time and carrier frequency, is studied in detail. A high precision estimation method based on triangular wavelet is proposed for pulse arrival time. This method is suitable for both LFM and PSK signals of conventional rectangular envelope signals. The simulation results show that the accuracy of the proposed method is more than 20% higher than that of the reference wavelet. Aiming at the carrier frequency estimation problem of LFM signal, a DPT FRFT two-dimensional interpolation algorithm is proposed. The simulation results show that the algorithm still keeps a relatively small relative error while shortening the computing time by 50%. A method based on wavelet ridge and adaptive mat is proposed to estimate the carrier frequency of PSK signal. The simulation results show that the carrier frequency relative error of the algorithm can reach less than .3when the SNR is about 4dB. Based on the research of modulation mode identification and intra-pulse parameter estimation, the technology development and simulation experiment of in-pulse analysis and target detection based on external emitter radar signal are carried out. The overall design of the external emitter radar signal receiver system is realized, the implementation flow of the intra pulse analysis subsystem and the target detection subsystem is designed in detail, and the simulation software of the external emitter signal processing receiver system is developed. Various simulation experiments are carried out. The results show that both the intra pulse analysis subsystem and the target detection subsystem have achieved the expected goal, which meet the requirements of engineering application. Finally, the accurate detection of the target has been realized, which shows that the proposed method and the system scheme are reasonable. It has high engineering application value.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN957.51

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