抗干扰天线中空时自适应算法的研究

发布时间：2018-01-07 17:14

本文关键词：抗干扰天线中空时自适应算法的研究　出处：《电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来,随着科学技术的不断发展,自适应阵列系统对于宽带信号的处理越来越频繁。相比于窄带信号的处理,宽带信号的处理更为复杂,由于宽带信号需要占用一定的频带宽度,为了在整个处理带宽内形成一致的波束形状,就需要更多的自由度来对波束进行调整。对宽带信号的处理一般分为两种方式,一种是空时自适应处理,它在空间域的基础上增加了一个时域的处理,对来自空间不同方位的信号进行空域和时域的联合处理;还有一种是基于频率的并行处理,它将入射的宽带信号进行傅里叶变换,在频域上提取信号各频点的数据,并行的对各个频点进行单独的处理。本文从阵列信号处理的信号模型和处理模型出发,基于窄带波束形成与宽带波束形成结论的一致性,首先从经典的窄带最小方差无失真响应算法出发,对算法在信源快速抖动的情况下的鲁棒性进行了研究。提出了一种联合算法,该算法结合了统计模型零陷展宽和最坏情况下的对角加载技术,在目标定位误差时,提高波束对方位快速变化的信源的鲁棒性。针对联合算法零陷深度的不足,提出了一种能够调节零陷深度的权值求解模型。在该模型下使用零陷展宽技术,通过调整因子的控制,能够获得较联合算法零陷更深的鲁棒波束。最后,通过空时域联合处理模型,将计算模型扩展到宽带模式。通过仿真展示了算法的相关结论,并算法间的性能比较。上述算法的性能依然依赖对目标方向的估计值,但是,在干扰很强的情况下,获得目标方向的信息是非常困难的。为了解决目标定位对算法性能的影响,提出了一种不需要目标定位信息的空时自适应算法。该算法对目标信号的频率失真较小,并且能够保证无法估计目标导向矢量情况下处理系统的性能。而且,在干扰突然增强时,系统的性能也有一定的保障。通过仿真给出了算法的波束结果,并对算法间的性能进行了分析和对比。
[Abstract]:In recent years, with the development of science and technology, the processing of wideband signal is more and more frequent in adaptive array system. Compared with narrowband signal processing, broadband signal processing is more complex. Because wideband signals need to occupy a certain bandwidth, in order to form a consistent beam shape in the whole processing bandwidth. The processing of wideband signals is generally divided into two ways, one is space-time adaptive processing, which adds a time domain processing on the basis of spatial domain. The signal from different azimuth in space is processed in spatial domain and time domain. The other is frequency based parallel processing, which carries out Fourier transform of the input wideband signal and extracts the data of each frequency point of the signal in the frequency domain. Parallel processing of each frequency point. From the array signal processing signal model and processing model, based on narrowband beamforming and wideband beamforming conclusion consistency. Firstly, based on the classical narrowband minimum variance distortionless response algorithm, the robustness of the algorithm in the case of fast source jitter is studied, and a joint algorithm is proposed. The algorithm combines the statistical model zero trapping broadening and the diagonal loading in the worst case to improve the robustness of the beam to the rapidly changing azimuth source when the target location error. This paper presents a weight solution model which can adjust the depth of zero trapping. By adjusting the factor, we can obtain a more robust beam than the joint algorithm by using the technique of zero trapping broadening. The computation model is extended to wideband mode through the joint processing model of space-time domain, and the relevant conclusions of the algorithm are demonstrated by simulation. The performance of the above algorithm still depends on the estimation of the target direction, but in the case of strong interference. It is very difficult to get the target direction information. In order to solve the impact of target location on the performance of the algorithm. This paper presents a space-time adaptive algorithm which does not need target location information. The algorithm has less frequency distortion and can guarantee the performance of the processing system under the condition of target orientation vector can not be estimated. When the interference increases suddenly, the system performance is guaranteed. The simulation results of the algorithm are given, and the performance of the algorithms is analyzed and compared.
【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】：TN973

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