杂波干扰环境下雷达恒虚警处理及其实现技术研究

发布时间：2018-04-05 06:09

本文选题：信号处理　切入点：信号检测　出处：《电子科技大学》2014年硕士论文

【摘要】：杂波干扰环境下的信号检测问题,一直是信号处理中的重要研究方向。恒虚警率(CFAR.Constant False Alarm Rate)处理技术能够在保持虚警概率恒定的条件下,实现对目标的检测。CFAR在得到广泛应用的同时,仍然面临着诸多挑战。由于杂波背景的统计特性变化与杂波边缘的影响给检测带来了很多困难。本文在经典的恒虚警处理理论的基础上,研究了频域的恒虚警处理方案与K分布海杂波背景下经典恒虚警检测器的检测性能。结合理论的研究,在FPGA上进行了实现。本文首先研究了经典的恒虚警处理理论。对均值类,有序统计类的恒虚警检测器进行了理论分析。比较了它们在均匀杂波背景下,检测性能之间的差异,以及在杂波边缘处对虚警的控制力。分析了各参数给检测性能带来的影响,为工程实现恒虚警处理技术提供了理论依据。接着研究了频域的恒虚警处理技术。分析了杂波与信号经过DFT处理后的分布情况。结合MTD-CFAR处理结构,通过仿真研究了MTD对恒虚警处理带来的影响。为了防止频域信号的扩展,达到减小“信号污染”的目的,结合脉冲多普勒雷达回波特性,研究了频域的CFAR处理方案。海杂波的相关性是影响CFAR检测性能的重要因素。在前面对瑞利杂波背景下经典的恒虚警处理理论研究的基础上,将经典的检测器拓展到了K分布下,研究了均值类与有序统计类CFAR处理方案在K分布海杂波下检测性能。与瑞利背景下的最优检测器做了比较。通过仿真与理论分析,得到了K分布参数给检测性能带来的影响。结合仿真数据,进一步验证了理论分析。最后,给出了工程上实现CFAR检测的具体方案。在实际的信号处理系统上,结合平台自身的特点,利用FPGA设计实现了CFAR处理。分析了具体的工程实现过程与步骤。在一维的CFAR处理实现结构的基础上,进一步导出了二维的CFAR处理结构。通过对处理数据过程的分析,优化了实现结构。系统通过了实际的检验。并且比较了实验结果与理论值。采用了本文设计的二维CFAR检测系统的实验结果表明,二维恒虚警处理能在控制住虚警的条件下,有效地检测出目标。本文通过讨论杂波干扰环境下的恒虚警技术,得到了经典检测器在K分布下的检测性能,并成功实现了距离-多普勒域的二维恒虚警处理。
[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.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN957.51

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