雷达调制方式识别技术研究与实现

发布时间：2018-07-25 15:24

【摘要】：在现代电子战环境中,电磁信号越来越复杂,信号密度越来越大,信号种类越来越多,新体制雷达信号不断涌现,因此,能够快速、有效地提取入射信号的各种参数是成功识别辐射源的关键因素。如果只是应用以往的信号参数已无法实现对新体制雷达信号的识别,只有通过提取新的且更能体现辐射源特征的参数才能够达到识别新体制雷达信号的目的。本文就雷达调制方式识别技术研究主要进行了三个方面的工作,分别为雷达信号脉内调制方式识别、雷达信号指纹特征识别和极化方式识别,在这三个方面分别提出了易于工程实现的识别方法,通过仿真验证了方法的正确性和可行性,并最终通过高速数字接收机实现,将其中一些方法应用到了实际的工程项目中。首先,本文对雷达信号脉内调制特征识别方法进行了研究,找到了一种先粗识别再细识别的调制类型识别方法,它首先计算信号的频谱带宽将信号粗分为调相信号和调频信号两类,然后采用具体的类内细分的方法实现了对常规信号、二相相移键控信号(BPSK)、四相相移键控信号(QPSK)、频率键控信号(FSK)、线性调频信号(LFM)、非线性调频信号(NLFM)和V型调频信号(VLFM)的识别,并且在数字接收机上对以上算法进行了实现,验证了该方法的有效性,具有很高的工程应用价值。其次,本文通过雷达信号指纹特征的定义,提取出了几种可以代表指纹特征的参数,并且通过对比几个参数的稳定性和抑制干扰的能力,最终确定以脉冲包络上升沿作为入射信号的指纹特征。通过计算并比较入射辐射源信号与模板信号的相像系数大小,从而实现对入射辐射源的识别。再次,本文通过雷达信号极化方式的不同表征,分析每种极化方式信号的不同特征,并且通过实际测试,提出了两种极化方式识别的方法,一种是通过变极化天线后的最小幅度输出来判别,另一种是通过计算不同极化下入射信号的幅度比值和相位差值来综合判定。对比两种方法的实现难易情况以及应用到的项目背景,最终选择第一种方法来进行硬件实现。然后,本文详细介绍了高速七通道数字接收机的硬件设计,主要从芯片选型、电源设计、芯片外围电路设计等几个方面进行了详细介绍,本文最终设计出了一款通用化、平台化的高速七通道数字接收机板卡。最后,介绍了系统中所选取的方法在高速七通道数字接收机上的软件实现过程和实际测试结果,编写了 VHDL程序。通过QuartusⅡ和Modelsim联合调试仿真,另外结合逻辑分析器SignalTap Ⅱ的在线观察,完成了软件程序的设计,验证了本文方法的正确性和可行性。
[Abstract]:In the modern electronic warfare environment, the electromagnetic signal is becoming more and more complex, the signal density is increasing, the variety of the signal is increasing, the radar signal of the new system is emerging constantly, therefore, can quickly, Effective extraction of various parameters of incident signal is the key factor to identify emitter successfully. If the recognition of the new radar signal can not be realized only by using the previous signal parameters, only by extracting the new parameters which can better reflect the characteristics of the emitter source can the recognition of the new system radar signal be achieved. In this paper, the research of radar modulation recognition technology is mainly carried out in three aspects, namely, radar signal intra-pulse modulation identification, radar signal fingerprint feature identification and polarization mode identification. In these three aspects, the identification method which is easy to be realized in engineering is put forward, and the correctness and feasibility of the method are verified by simulation. Finally, some of the methods are applied to practical engineering projects through high-speed digital receiver. Firstly, in this paper, the method of modulation feature recognition in radar signal is studied, and a modulation type recognition method based on coarse recognition and fine recognition is found. It first calculates the spectrum bandwidth of the signal and divides the signal into two categories: phase modulation signal and frequency modulation signal, and then realizes the conventional signal by using the specific subdivision method within the class. Two phase shift keying signal (BPSK), four phase shift keying signal (QPSK), frequency shift keying signal (FSK), linear frequency modulated signal (LFM), nonlinear frequency modulated signal (NLFM) and V type frequency modulated signal (VLFM) are identified and implemented in digital receiver. The validity of the method is verified, and the method has high engineering application value. Secondly, through the definition of fingerprint feature of radar signal, several parameters which can represent the fingerprint feature are extracted, and the stability of several parameters and the ability of suppressing interference are compared. Finally, the fingerprint characteristics with pulse envelope rising edge as incident signal are determined. By calculating and comparing the image coefficient between the incident emitter signal and the template signal, the identification of the incident emitter can be realized. Thirdly, through the different characterization of radar signal polarization mode, this paper analyzes the different characteristics of each polarization signal, and through the actual test, puts forward two polarimetric recognition methods. One is based on the minimum amplitude output of the variable polarization antenna, the other is by calculating the amplitude ratio and phase difference of the incident signal under different polarization conditions. By comparing the implementation of the two methods and the project background, the first method is chosen to implement the hardware. Then, this paper introduces the hardware design of high-speed seven-channel digital receiver in detail, mainly from chip selection, power supply design, chip peripheral circuit design and so on. High-speed seven-channel digital receiver board based on platform. Finally, the software implementation process and the actual test results of the selected method in the high-speed seven-channel digital receiver are introduced, and the VHDL program is written. Through the joint debugging simulation of Quartus 鈪，

本文编号：2144238