【摘要】：在現(xiàn)代電子戰(zhàn)環(huán)境中,電磁信號越來越復雜,信號密度越來越大,信號種類越來越多,新體制雷達信號不斷涌現(xiàn),因此,能夠快速、有效地提取入射信號的各種參數(shù)是成功識別輻射源的關(guān)鍵因素。如果只是應(yīng)用以往的信號參數(shù)已無法實現(xiàn)對新體制雷達信號的識別,只有通過提取新的且更能體現(xiàn)輻射源特征的參數(shù)才能夠達到識別新體制雷達信號的目的。本文就雷達調(diào)制方式識別技術(shù)研究主要進行了三個方面的工作,分別為雷達信號脈內(nèi)調(diào)制方式識別、雷達信號指紋特征識別和極化方式識別,在這三個方面分別提出了易于工程實現(xiàn)的識別方法,通過仿真驗證了方法的正確性和可行性,并最終通過高速數(shù)字接收機實現(xiàn),將其中一些方法應(yīng)用到了實際的工程項目中。首先,本文對雷達信號脈內(nèi)調(diào)制特征識別方法進行了研究,找到了一種先粗識別再細識別的調(diào)制類型識別方法,它首先計算信號的頻譜帶寬將信號粗分為調(diào)相信號和調(diào)頻信號兩類,然后采用具體的類內(nèi)細分的方法實現(xiàn)了對常規(guī)信號、二相相移鍵控信號(BPSK)、四相相移鍵控信號(QPSK)、頻率鍵控信號(FSK)、線性調(diào)頻信號(LFM)、非線性調(diào)頻信號(NLFM)和V型調(diào)頻信號(VLFM)的識別,并且在數(shù)字接收機上對以上算法進行了實現(xiàn),驗證了該方法的有效性,具有很高的工程應(yīng)用價值。其次,本文通過雷達信號指紋特征的定義,提取出了幾種可以代表指紋特征的參數(shù),并且通過對比幾個參數(shù)的穩(wěn)定性和抑制干擾的能力,最終確定以脈沖包絡(luò)上升沿作為入射信號的指紋特征。通過計算并比較入射輻射源信號與模板信號的相像系數(shù)大小,從而實現(xiàn)對入射輻射源的識別。再次,本文通過雷達信號極化方式的不同表征,分析每種極化方式信號的不同特征,并且通過實際測試,提出了兩種極化方式識別的方法,一種是通過變極化天線后的最小幅度輸出來判別,另一種是通過計算不同極化下入射信號的幅度比值和相位差值來綜合判定。對比兩種方法的實現(xiàn)難易情況以及應(yīng)用到的項目背景,最終選擇第一種方法來進行硬件實現(xiàn)。然后,本文詳細介紹了高速七通道數(shù)字接收機的硬件設(shè)計,主要從芯片選型、電源設(shè)計、芯片外圍電路設(shè)計等幾個方面進行了詳細介紹,本文最終設(shè)計出了一款通用化、平臺化的高速七通道數(shù)字接收機板卡。最后,介紹了系統(tǒng)中所選取的方法在高速七通道數(shù)字接收機上的軟件實現(xiàn)過程和實際測試結(jié)果,編寫了 VHDL程序。通過QuartusⅡ和Modelsim聯(lián)合調(diào)試仿真,另外結(jié)合邏輯分析器SignalTap Ⅱ的在線觀察,完成了軟件程序的設(shè)計,驗證了本文方法的正確性和可行性。
[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，

本文編號：2144238