宽带自适应波束形成技术的研究和实现

发布时间：2018-05-21 16:09

本文选题：宽带波束形成 + 恒定束宽　；参考：《南京理工大学》2017年硕士论文

【摘要】：自适应波束形成可以通过对接收信号的处理,更有效地提取有用信号,同时抑制干扰,在雷达、通信等系统中广泛应用。随着宽带信号处理技术的发展,宽带自适应波束形成技术成为了阵列信号处理领域的研究热点之一。然而,由于宽带信号包含大量频率分量,宽带波束形成存在输出频率一致性差和计算复杂度高两个主要问题。本文围绕恒定束宽宽带波束形成和降复杂度的自适应波束形成技术展开研究,主要工作如下:1.分析对比了宽带波束形成的频域、抽头延迟线(TDL)和阵元延迟线(SDL)结构。介绍了一种新的基于空间响应偏差(SRV)因子的线性约束最小方差(LCMV)算法,提高了输出的频率不变性,同时研究了该算法中权重因子对抗干扰性能和频率不变性的影响。2.研究了基于波束空间的宽带波束形成算法,基于最新的频率不变波束形成器(FIB)提出了一种新的转换矩阵设计方法,提高了输出方向图的频率一致性。介绍了一种基于FIB的波束空间处理结构,同时针对波束不完全正交问题引入了特征分解技术,在保证恒定束宽的同时提高了抗干扰能力。3.研究了多级维纳滤波器(MSWF)和联合迭代优化(JIO)两种降秩结构,介绍了利用递归最小二乘(RLS)算法求解JIO结构目标函数的方法,同时基于最小均方(LMS)算法推导了新的JIO结构迭代公式,进一步降低了计算复杂度。此后,提出了新的加入SRV因子的JIO-LMS算法,提高了输出方向图的频率不变性。4.基于北斗导航抗干扰系统,将基于TDL结构的宽带自适应波束形成算法在DSP上实现,并通过系统实验验证了算法的性能。
[Abstract]:Adaptive beamforming can extract useful signals more effectively and suppress interference by processing received signals. It is widely used in radar, communication and other systems. With the development of wideband signal processing technology, wideband adaptive beamforming technology has become one of the hotspots in the field of array signal processing. However, because wideband signals contain a large number of frequency components, there are two main problems in wideband beamforming: poor output frequency consistency and high computational complexity. This paper focuses on the constant beamwidth wideband beamforming and adaptive beamforming with reduced complexity. The main work is as follows: 1. The structure of broadband beamforming in frequency domain, tap delay line (TDL) and array element delay line (SDL) is analyzed and compared. This paper introduces a new linear constrained minimum variance (LCMV) algorithm based on spatial response deviation (SRV) factor, which improves the frequency invariance of output. At the same time, the influence of weight factor on anti-jamming performance and frequency invariance is studied. Broadband beamforming algorithm based on beamspace is studied. Based on the latest frequency invariant beamforming (FIB), a new design method of conversion matrix is proposed to improve the frequency consistency of the output pattern. A beamspace processing structure based on FIB is introduced in this paper. The eigen-decomposition technique is introduced to solve the problem of incomplete orthogonal beam-beam, which ensures the constant beam width and improves the anti-jamming ability. In this paper, two kinds of rank reduction structures, multistage Wiener filter (MSWF) and joint iterative optimization (JIO), are studied. The method of solving the objective function of JIO structure by using the recursive least squares algorithm is introduced. At the same time, based on the least mean square (LMS) algorithm, a new iterative formula of JIO structure is derived. The computational complexity is further reduced. After that, a new JIO-LMS algorithm with SRV factor is proposed to improve the frequency invariance of the output pattern. 4. Based on Beidou navigation anti-jamming system, the wideband adaptive beamforming algorithm based on TDL structure is implemented on DSP, and the performance of the algorithm is verified by system experiments.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN911.7;TN967.1

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