子阵级空时自适应处理方法研究

1、摘要自适应数字波束形成（adaptive digital beamforming，ADBF）技术是相控阵雷达关键技术之一。现代相控阵雷达通常包含成千上万个阵元，通常采用子阵结构并且只可以得到子阵输出。基于线性约束最小方差（linearly constrained minimum-variance， LCMV）准则的直接子阵加权（direct subarray weighting， DSW）结构是一种有效的ADBF方法，但是存在阵列误差的条件下其波束将发生畸变。此外，随着相控阵技术不断发展，宽带信号以其独特的优势在相控阵系统的应用中受到了广泛关注，采用宽带信号的多功能相控阵雷达将是现代雷达发展的

2、一个重要方向。本文针对三种具有辅助阵列的阵列结构分别研究了窄带ADBF和宽带空时自适应处理（space-time adaptive processing, STAP）方法，并给出了相应的波束形成及性能分析。首先给出了子阵级广义旁瓣对消器（GSLC）结构的窄带ADBF三种实现算法：Wiener-Hopf方程方法、Nickel的常规方法、Householder变换方法。在阵列误差条件下，GSLC能有效保持波束形状和自适应性能，并且采用均匀子阵划分和归一化方法可以得到与静态方向图一致的旁瓣电平。接着针对宽带信号和宽带干扰，给出了GSLC的子阵级STAP方法，依然采用上述三种方法实现。然后针对子阵级S

3、LC结构，给出ADBF与STAP实现算法：基于Wiener-Hopf方程方法和HA算法。子阵级主阵列用于形成静态和波束，而阵元级辅助阵列用于自适应抑制干扰。最后对子阵级旁瓣消除器（SLC）的STAP结构加以改进，在辅助阵列采用子阵级处理，并使辅助阵列远离主阵列，降低软硬件成本的同时也提高了抑制宽带主瓣干扰的性能。给出了基于最小方差准则的方法和HA算法两种实现方法。对所提出的各种方法进行了仿真，结果证明所提出的方法是有效的。关键词自适应波束形成，干扰抑制，STAP，宽带干扰，子阵级相控阵AbstractThe technique of adaptive digital beamforming (

4、ADBF) plays a key role in Phase Array Radar System (PARS). PARS consist of numerous elements which easily form the subarray structure and get the subarray output. Direct subarray weighting (DSW) method based on linearly constrained minim-variance(LCMV) criterion is an effective way to realize ADBF,

5、but its performance go bad when the array errors, such as amplitude error and phase error, increase. Generalized sidelobe canceller (GSLC) architecture possesses robust property to these errors. Moreover, with the development of phased array technique, the application of broadband signal has been wi

6、dely focused in phased array system for its unique advantage. Multi-function phased array radar which adopts broadband signal is the developing trends for modern radar.In this paper, three techniques with auxiliary arrays are adopted into ADBF for narrow band and STAP for wide band, and the performa

7、nce is analysed.In the first, the three kinds of realization of narrow band ADBF algorithm which based on GSLC structure is give out. They are Winer-Hoopf method, Nickel method and Householder method. In the severe error environment, the performance of GSLC is still good. In the same time, the combi

8、nation of uniform subarraying and normalized method can obtain the same sidelobe level compared with quiescent pattern. Then, the wideband signal and wideband jamming are discussed, and realized by three kinds of method, too. Then SLC architecture are discussed, and the methods for ADBF and STAP are

9、 realized: Winer-Hopf equation and HA arithmetic. The main array is used for forming the quicscent beam and the auxiliary one is for forming notch adaptively. Finally, the SLC at subarray for STAP is improved. The auxiliary array is adopted at subarray level, and it is far away from the main array.

10、As a result, hardware cost is saved much and the performance for suppressing mainlobe jammer is improved. And two methods, HA arithmetic and Least-variance method, for realization are discussed.We simulate and analyze all the presented algorithms. The simulation results demonstrate the validity of t

11、he algorithms.Keywords adaptive beamforming, jammer suppression, STAP, broadband jammer，phased array at subarray level不要删除行尾的分节符，此行不会被打印- 4 -目 录摘要IAbstractII第1章 绪论11.1 课题来源及研究的目的和意义11.2 国内外在该方向的研究现状及分析41.3 论文结构安排6第2章 基于GSLC的子阵级ADBF方法82.1 引言82.2 子阵级DSW结构82.2.1 子阵级信号模型82.2.2 基于LCMV的DSW方法102.3 子阵级GSLC结

12、构及其原理112.3.1 基于Wiener-Hopf的GSLC122.3.2 常规的子阵级GSLC132.3.3 基于Householder变换的子阵级GSLC152.3.4 仿真结果及分析162.4 归一化子阵级GSLC202.4.1 重叠法原理202.4.2 归一化原理212.4.3 仿真结果及分析222.5 本章小结23第3章 基于GSLC的子阵级STAP方法243.1 引言243.2 宽带信号模型243.3 宽带阵列结构263.4 子阵级STAP方法283.4.1 信号模型293.4.2 Wiener-Hopf方法的STAP313.4.3 常规方法的STAP313.4.4 Householder变换方法的STAP323.5 仿真结果及分析333.6 本章小结35第4章 基于SLC结构的子阵级STAP方法374.1 引言374.2 子阵级SLC的ADBF374.2.1 阵列模型374.2.2 Wiener-Hopf方法384.2.3 HA算法394.2.4 输出SINR414.2.5 仿真结果及分析414.3 ST