基于多级维纳滤波的非均匀环境杂波抑制方法研究

发布时间：2018-01-13 11:07

本文关键词：基于多级维纳滤波的非均匀环境杂波抑制方法研究　出处：《电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：空时自适应信号处理技术被广泛应用于生物医学工程等领域,在生命探测领域中生物雷达指能够探测生命特征的雷达,它结合了雷达原理和生物医学工程,可穿透性强,可在较远的距离内探测到生命体的生命信号。相控阵技术在雷达中得到了广泛应用,其中共形相控阵,因为其扫描范围宽,便于集成等独特优势受到世界各国的普遍重视。不同于传统的平面相控阵雷达,共形阵雷达接收的杂波往往在不同方向都呈现出一定的非均匀性,这种非均匀性导致了我们对杂波协方差矩阵的估计误差增大,使得传统空时自适应信号处理算法的性能严重下降。本文研究的主要目的就是要在考虑工程实现的情况下发展新的自适应处理算法来抑制共形相控阵面临的非均匀杂波,为此本文开展了以下工作:本文首先以机头共形阵为例建立了杂波数学模型,通过仿真和分析共形阵雷达杂波特性的基础上,提出采用俯仰向空域滤波作为预处理方法来改善杂波的非均匀性,同时为进一步提高杂波抑制性能,后续级联了改进的协方差矩阵加权算法以修正估计的杂波协方差矩阵。协方差矩阵求逆是空时自适应处理算法中运算量最大的部分,因此为了降低运算量,本文采用基于相关相减结构的多级维纳滤波代替协方差矩阵求逆来得到抑制杂波的自适应滤波权值,最终本文提出了一种基于俯仰向空域滤波的协方差矩阵加权多级维纳滤波算法,用于抑制共形阵雷达杂波。为了验证本文算法的正确性、有效性以及通用性,我们在毫米波、米波、分米波等不同工作波长以及不同结构的共形阵下对该算法的杂波抑制性能进行了仿真。最后还对本文算法和现有算法的运算量进行了对比分析和仿真。仿真结果表明,本文方法抑制共形阵雷达杂波的综合性能优于现有其它方法,且计算复杂度低,收敛速度快,便于工程实现,在共形阵雷达杂波抑制中具有实际应用前景。
[Abstract]:Space-time adaptive signal processing technology is widely used in biomedical engineering and other fields. In the field of life detection, biological radar refers to the radar which can detect the characteristics of life. It combines the principle of radar and biomedical engineering. The technology of phased array is widely used in radar, in which conformal phased array is widely used because of its wide scanning range. Different from the traditional planar phased array radar, the clutter received by conformal array radar often presents certain inhomogeneity in different directions. This inhomogeneity results in an increase in the estimation error of the clutter covariance matrix. The performance of the traditional space-time adaptive signal processing algorithm is seriously degraded. The main purpose of this paper is to develop a new adaptive processing algorithm to suppress the inhomogeneity of conformal phased array under the consideration of engineering implementation. Even clutter. In this paper, the following works are carried out: firstly, the mathematical model of clutter is established by taking the conformal array as an example, and the clutter characteristics of conformal array radar are simulated and analyzed. Pitch spatial filtering is proposed as a preprocessing method to improve the heterogeneity of clutter and to further improve the performance of clutter suppression. The improved covariance matrix weighting algorithm is cascaded to modify the estimated clutter covariance matrix. The inverse of covariance matrix is the largest part of the space-time adaptive processing algorithm, so in order to reduce the amount of computation. In this paper, multistage Wiener filter based on correlation subtraction structure is used instead of covariance matrix to obtain adaptive filtering weights for clutter suppression. Finally, this paper proposes a covariance matrix weighted multistage Wiener filtering algorithm based on pitch spatial filtering, which is used to suppress conformal array radar clutter. In order to verify the correctness, effectiveness and versatility of the proposed algorithm. We're in millimeter wave, meter wave. The clutter suppression performance of the algorithm is simulated under conformal array with different wavelengths and different structures. Finally, the computational complexity of this algorithm and the existing algorithms are compared and analyzed. The simulation results are given. To show. In this paper, the synthesis performance of conformal array radar clutter suppression is superior to that of other existing methods, and the computational complexity is low, the convergence speed is fast, and it is easy to be realized in engineering, so it has a practical application prospect in conformal array radar clutter suppression.
【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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