【摘要】：現(xiàn)代技術(shù)發(fā)展日新月異,雷達(dá)研究周期越來(lái)越長(zhǎng),雷達(dá)工作環(huán)境也越來(lái)越復(fù)雜,研究一部新型雷達(dá),需要進(jìn)行大量的外場(chǎng)測(cè)試來(lái)驗(yàn)證其性能�，F(xiàn)代雷達(dá)功能日益復(fù)雜和多樣化,在設(shè)計(jì)和分析雷達(dá)過(guò)程中需要考慮大量的隨機(jī)因素和非線性影響,另外在實(shí)際實(shí)驗(yàn)環(huán)境中,受制約的因素有很多,參數(shù)的離散性很大,有時(shí)為了測(cè)得一個(gè)較為準(zhǔn)確的參數(shù),需要反復(fù)進(jìn)行多次實(shí)驗(yàn),這樣,所耗費(fèi)的人力物力是非常巨大的,不僅增加了科研經(jīng)費(fèi),也延誤了科研的進(jìn)度,這些因素對(duì)雷達(dá)的設(shè)計(jì)和測(cè)試等帶來(lái)了很大的困難和不便。相對(duì)來(lái)說(shuō),采用雷達(dá)信號(hào)模擬的方式來(lái)設(shè)計(jì)、測(cè)試?yán)走_(dá),便有了很多的優(yōu)點(diǎn)。雷達(dá)信號(hào)模擬技術(shù)主要研究目標(biāo)特性模型,電磁環(huán)境干擾特性模型以及回波實(shí)時(shí)模擬。本文主要研究的是回波實(shí)時(shí)模擬技術(shù)。當(dāng)需要實(shí)時(shí)模擬多個(gè)目標(biāo)時(shí),對(duì)硬件資源的要求比較高。本文給出了基于FPGA平臺(tái),可實(shí)時(shí)并行模擬4個(gè)目標(biāo)的雷達(dá)回波模擬系統(tǒng)的方案,并介紹了測(cè)試方法和測(cè)試結(jié)果。本文首先根據(jù)雷達(dá)原理介紹了點(diǎn)目標(biāo)雷達(dá)回波信號(hào)的基本模型,分析了線性調(diào)頻信號(hào)的特點(diǎn),詳細(xì)的介紹了目標(biāo)的起伏模型,并以Swerling IV型分布為例,講述了產(chǎn)生隨機(jī)數(shù)的方法,給出了含4個(gè)子陣元的相控陣天線方向圖函數(shù)模型,介紹了如何實(shí)現(xiàn)和、差波束調(diào)制,分析了任意運(yùn)動(dòng)軌跡目標(biāo)的運(yùn)動(dòng)模型。然后文章講述了具體實(shí)現(xiàn)方法。對(duì)于天線方向圖函數(shù)調(diào)制和目標(biāo)起伏調(diào)制,方向圖數(shù)據(jù)和目標(biāo)起伏數(shù)據(jù)均采用上位機(jī)預(yù)先產(chǎn)生,下載到目標(biāo)板再讀取的方式。正余弦波形的產(chǎn)生采用了Cordic算法來(lái)實(shí)現(xiàn),只需要簡(jiǎn)單的移位和加減法既可以實(shí)現(xiàn)任意頻率的正余弦波形的產(chǎn)生。為了節(jié)省硬件資源,濾波器的采用了高效的多相結(jié)構(gòu)。本文還詳細(xì)介紹了如何實(shí)現(xiàn)對(duì)各個(gè)模塊的控制,如何模擬多普勒調(diào)制、距離延遲及天線的掃描。在硬件實(shí)現(xiàn)之前,對(duì)整個(gè)模擬系統(tǒng)做了MATLAB仿真。最后介紹了基于FPGA的多目標(biāo)回波模擬系統(tǒng)的測(cè)試方法,首先單獨(dú)測(cè)試了各個(gè)模塊的功能,然后系統(tǒng)聯(lián)調(diào)測(cè)試,并且給出了相應(yīng)的測(cè)試結(jié)果。本文的創(chuàng)新點(diǎn)在于克服了以往只是對(duì)單個(gè)目標(biāo)的模擬,實(shí)現(xiàn)了對(duì)4個(gè)運(yùn)動(dòng)目標(biāo)的并行實(shí)時(shí)回波模擬,并做了詳細(xì)的分析,給出了一些高效的算法,節(jié)省了所需的硬件資源。
[Abstract]:With the rapid development of modern technology, the research period of radar becomes longer and longer, and the working environment of radar becomes more and more complex. To study a new type of radar, it is necessary to carry out a lot of external field tests to verify its performance. The function of modern radar is becoming more and more complex and diversified. In the process of radar design and analysis, a large number of random factors and nonlinear effects need to be considered. In addition, in the practical experimental environment, there are many restricted factors and the discreteness of parameters is very large. Sometimes, in order to measure a more accurate parameter, repeated experiments need to be carried out, so that the manpower and material resources spent are very huge, not only increasing the funding for scientific research, but also delaying the progress of scientific research. These factors bring great difficulty and inconvenience to radar design and test. Relatively speaking, using radar signal simulation to design, test radar, there are many advantages. Radar signal simulation technology mainly studies target characteristic model, electromagnetic environment interference characteristic model and echo real-time simulation. In this paper, the echo real-time simulation technology is mainly studied. When real-time simulation of multiple targets is needed, the requirements for hardware resources are high. In this paper, the scheme of radar echo simulation system based on FPGA platform and real-time parallel simulation of four targets is presented, and the testing methods and results are introduced. In this paper, the basic model of radar echo signal of point target is introduced according to the principle of radar, the characteristic of LFM signal is analyzed, the undulating model of target is introduced in detail, and the method of generating random number is described by taking the distribution of Swerling IV as an example. The pattern function model of phased array antenna with four sub-array elements is given, and how to realize sum and differential beam modulation is introduced, and the motion model of arbitrary trajectory target is analyzed. Then the article describes the concrete implementation method. For antenna pattern function modulation and target fluctuation modulation, the pattern data and target fluctuation data are pre-generated by the host computer and then downloaded to the target board. Cordic algorithm is used to generate sine and cosine waveforms. Only simple shift, addition and subtraction are needed to generate sine and cosine waveforms with arbitrary frequency. In order to save hardware resources, the filter adopts an efficient multi-phase structure. How to realize the control of each module, how to simulate Doppler modulation, range delay and antenna scanning are also introduced in detail. Before the hardware implementation, the whole simulation system is simulated with MATLAB. Finally, the testing method of the multi-target echo simulation system based on FPGA is introduced. First, the function of each module is tested separately, then the system debugging test is carried out, and the corresponding test results are given. The innovation of this paper is to overcome the previous simulation of a single target, realize the parallel real-time echo simulation of four moving targets, and make a detailed analysis, give some efficient algorithms, and save the required hardware resources.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：TN955

【參考文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

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本文編號(hào)：2433955