本文選題：信號處理　切入點：信號檢測　出處：《電子科技大學》2014年碩士論文

【摘要】：雜波干擾環(huán)境下的信號檢測問題,一直是信號處理中的重要研究方向。恒虛警率(CFAR.Constant False Alarm Rate)處理技術(shù)能夠在保持虛警概率恒定的條件下,實現(xiàn)對目標的檢測。CFAR在得到廣泛應用的同時,仍然面臨著諸多挑戰(zhàn)。由于雜波背景的統(tǒng)計特性變化與雜波邊緣的影響給檢測帶來了很多困難。本文在經(jīng)典的恒虛警處理理論的基礎(chǔ)上,研究了頻域的恒虛警處理方案與K分布海雜波背景下經(jīng)典恒虛警檢測器的檢測性能。結(jié)合理論的研究,在FPGA上進行了實現(xiàn)。本文首先研究了經(jīng)典的恒虛警處理理論。對均值類,有序統(tǒng)計類的恒虛警檢測器進行了理論分析。比較了它們在均勻雜波背景下,檢測性能之間的差異,以及在雜波邊緣處對虛警的控制力。分析了各參數(shù)給檢測性能帶來的影響,為工程實現(xiàn)恒虛警處理技術(shù)提供了理論依據(jù)。接著研究了頻域的恒虛警處理技術(shù)。分析了雜波與信號經(jīng)過DFT處理后的分布情況。結(jié)合MTD-CFAR處理結(jié)構(gòu),通過仿真研究了MTD對恒虛警處理帶來的影響。為了防止頻域信號的擴展,達到減小“信號污染”的目的,結(jié)合脈沖多普勒雷達回波特性,研究了頻域的CFAR處理方案。海雜波的相關(guān)性是影響CFAR檢測性能的重要因素。在前面對瑞利雜波背景下經(jīng)典的恒虛警處理理論研究的基礎(chǔ)上,將經(jīng)典的檢測器拓展到了K分布下,研究了均值類與有序統(tǒng)計類CFAR處理方案在K分布海雜波下檢測性能。與瑞利背景下的最優(yōu)檢測器做了比較。通過仿真與理論分析,得到了K分布參數(shù)給檢測性能帶來的影響。結(jié)合仿真數(shù)據(jù),進一步驗證了理論分析。最后,給出了工程上實現(xiàn)CFAR檢測的具體方案。在實際的信號處理系統(tǒng)上,結(jié)合平臺自身的特點,利用FPGA設(shè)計實現(xiàn)了CFAR處理。分析了具體的工程實現(xiàn)過程與步驟。在一維的CFAR處理實現(xiàn)結(jié)構(gòu)的基礎(chǔ)上,進一步導出了二維的CFAR處理結(jié)構(gòu)。通過對處理數(shù)據(jù)過程的分析,優(yōu)化了實現(xiàn)結(jié)構(gòu)。系統(tǒng)通過了實際的檢驗。并且比較了實驗結(jié)果與理論值。采用了本文設(shè)計的二維CFAR檢測系統(tǒng)的實驗結(jié)果表明,二維恒虛警處理能在控制住虛警的條件下,有效地檢測出目標。本文通過討論雜波干擾環(huán)境下的恒虛警技術(shù),得到了經(jīng)典檢測器在K分布下的檢測性能,并成功實現(xiàn)了距離-多普勒域的二維恒虛警處理。
[Abstract]:Signal detection in clutter interference environment has been an important research direction in signal processing.CFAR.constant False Alarm rate (CFAR.Constant False Alarm rate) processing technology can realize the detection of target under the condition of keeping the false alarm probability constant, and it still faces many challenges while it is widely used.Because of the statistical characteristics of clutter background and the influence of clutter edge, it is difficult to detect.Based on the classical CFAR theory, this paper studies the CFAR processing scheme in frequency domain and the detection performance of classical CFAR detector in the background of K-distributed sea clutter.Combined with the research of theory, it is implemented on FPGA.In this paper, we first study the classical CFAR theory.The CFAR detectors of mean class and ordered statistic class are theoretically analyzed.The difference between the detection performance and the false alarm control force at the edge of the clutter is compared under the uniform clutter background.The influence of the parameters on the detection performance is analyzed, which provides a theoretical basis for the engineering implementation of CFAR processing technology.Then the CFAR processing technology in frequency domain is studied.The distribution of clutter and signal after DFT processing is analyzed.Combined with MTD-CFAR processing structure, the influence of MTD on CFAR processing is studied by simulation.In order to prevent the spread of frequency-domain signals and reduce the "signal pollution", the CFAR processing scheme in frequency domain is studied based on the echo characteristics of pulsed Doppler radar.The correlation of sea clutter is an important factor affecting the detection performance of CFAR.Based on the research of classical CFAR theory in Rayleigh clutter background, the classical detector is extended to K distribution, and the detection performance of mean class and ordered statistical CFAR processing scheme under K-distribution sea clutter is studied.It is compared with the optimal detector in Rayleigh background.Through simulation and theoretical analysis, the effect of K distribution parameters on detection performance is obtained.Combined with the simulation data, the theoretical analysis is further verified.Finally, the project of CFAR detection in engineering is given.In the actual signal processing system, combined with the characteristics of the platform itself, CFAR processing is designed by using FPGA.The concrete engineering realization process and steps are analyzed.On the basis of one-dimensional CFAR processing implementation structure, the two-dimensional CFAR processing structure is further derived.By analyzing the process of data processing, the implementation structure is optimized.The system has passed the actual test.The experimental results are compared with the theoretical values.The experimental results of the two-dimensional CFAR detection system designed in this paper show that the two-dimensional CFAR processing can effectively detect the target under the condition of controlling the false alarm rate.In this paper, the detection performance of classical detector under K-distribution is obtained by discussing the CFAR technology in clutter interference environment, and the 2-D CFAR processing in range-Doppler domain is successfully realized.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN957.51

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相關(guān)博士學位論文 前1條

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本文編號：1713503