本文選題：測頻 + 數(shù)字信道化��； 參考：《西安電子科技大學(xué)》2014年碩士論文

【摘要】：未來的戰(zhàn)爭是信息的戰(zhàn)爭,所以如何快速地在最大程度上獲取對方的信息成為電子偵察的主要任務(wù)。信號的載頻是其中的重要參數(shù),測頻的精度決定了后續(xù)信號分選與識別時對輻射源的分辨率。數(shù)字測頻技術(shù)實時性好、頻率分辨率高、可以處理時域重疊的多信號、系統(tǒng)穩(wěn)定,基于這些優(yōu)勢,數(shù)字測頻技術(shù)顯得越來越重要。偵察接收機(jī)處理的目標(biāo)信號一般具有較大的帶寬,使用奈奎斯特采樣方法設(shè)計系統(tǒng)會產(chǎn)生信號處理速度難以匹配采樣速率的問題,可以采用欠采樣對信號數(shù)字化,但會導(dǎo)致頻率模糊,需要使用解模糊算法恢復(fù)信號的真實頻率。本文首先研究了基于STFT結(jié)構(gòu)的數(shù)字信道化技術(shù),討論了加窗DFT的濾波特性,分析其實現(xiàn)數(shù)字信道化的基本原理,給出了算法模型;并且以輸入信號為單載頻和線性調(diào)頻信號為例,仿真分析了算法的工作流程,給出了信號時域及頻域參數(shù)的估計方法;接下來詳細(xì)討論了STFT算法中的一些問題,例如檢測門限的設(shè)定、窗函數(shù)長度選擇、滑動點數(shù)的確定等問題,分析了不同參數(shù)產(chǎn)生的影響,便于使算法在滿足系統(tǒng)性能指標(biāo)要求的前提下具有較高的工作效率;討論了基于STFT信道化對雷達(dá)信號調(diào)制方式的分析識別,給出了可用的分選準(zhǔn)則;討論了三種信道化后的精測頻算法,并分別對算法的性能進(jìn)行了仿真分析;研究了在同時多信號情況下大信號對小信號的影響,分析了窗函數(shù)的作用并給出了窗函數(shù)的選擇依據(jù)。最后在欠采樣的條件下,討論了欠采樣產(chǎn)生頻率模糊的原因,給出四種典型的解模糊結(jié)構(gòu),包括單通道延遲法、正交雙通道延遲法、雙速率解模糊法與MUSIC解模糊算法;分別仿真了解模糊過程,分析了解模糊原理,并指出了各自的優(yōu)缺點;提出了將STFT信道化與欠采樣結(jié)合使用的測頻方法,并以雙速率解模糊為例,仿真驗證方法的可行性,給出使用時的注意事項,對實際硬件實現(xiàn)有借鑒意義。
[Abstract]:The future war is the war of information, so how to obtain the information of the other party quickly becomes the main task of electronic reconnaissance. The carrier frequency of the signal is an important parameter. The accuracy of the frequency measurement determines the resolution of the emitter when the subsequent signal is sorted and identified. Digital frequency measurement technology is more and more important because of its good real-time performance and high frequency resolution. It can deal with multi-signal overlapping in time domain and the system is stable. Based on these advantages, digital frequency measurement technology is becoming more and more important. The target signal processed by the reconnaissance receiver generally has a large bandwidth. Using Nyquist sampling method to design the system will cause the problem that the signal processing speed is difficult to match the sampling rate, so the under-sampling can be used to digitize the signal. But it can cause the frequency blur, so it is necessary to restore the true frequency of the signal by using the deblurring algorithm. In this paper, the digital channelization technology based on STFT structure is studied, the filtering characteristic of windowed DFT is discussed, the basic principle of digital channelization is analyzed, and the algorithm model is given. Taking input signal as single carrier frequency signal and linear frequency modulation signal as an example, the working flow of the algorithm is simulated and the estimation method of signal parameters in time domain and frequency domain is given. Then, some problems in STFT algorithm are discussed in detail. For example, the setting of detection threshold, the selection of window function length, the determination of sliding points and so on. The influence of different parameters is analyzed, which makes the algorithm more efficient on the premise of meeting the requirements of system performance. This paper discusses the analysis and identification of radar signal modulation mode based on STFT channelization, presents the available sorting criteria, discusses three kinds of fine frequency measurement algorithms after channelization, and analyzes the performance of the algorithm by simulation. The influence of large signal on small signal in the case of simultaneous multi-signal is studied. The function of window function is analyzed and the selection basis of window function is given. Finally, under the condition of undersampling, the causes of frequency ambiguity are discussed, and four typical structures are given, including single channel delay method, orthogonal double channel delay method, dual rate deblurring method and music deblurring algorithm. The fuzzy process is simulated, the fuzzy principle is analyzed, and their advantages and disadvantages are pointed out, and a frequency measurement method which combines STFT channelization with under-sampling is proposed, and the feasibility of the method is verified by simulation. The points for attention in use are given, which can be used for reference in practical hardware implementation.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN971.1

【參考文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 都佰勝;欠采樣測頻與信號處理技術(shù)[D];西安電子科技大學(xué);2009年

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本文編號：2086859