子陣級空時自適應(yīng)處理方法研究

1、摘要自適應(yīng)數(shù)字波束形成（adaptive digital beamforming，ADBF）技術(shù)是相控陣雷達關(guān)鍵技術(shù)之一。現(xiàn)代相控陣雷達通常包含成千上萬個陣元，通常采用子陣結(jié)構(gòu)并且只可以得到子陣輸出。基于線性約束最小方差（linearly constrained minimum-variance， LCMV）準(zhǔn)則的直接子陣加權(quán)（direct subarray weighting， DSW）結(jié)構(gòu)是一種有效的ADBF方法，但是存在陣列誤差的條件下其波束將發(fā)生畸變。此外，隨著相控陣技術(shù)不斷發(fā)展，寬帶信號以其獨特的優(yōu)勢在相控陣系統(tǒng)的應(yīng)用中受到了廣泛關(guān)注，采用寬帶信號的多功能相控陣雷達將是現(xiàn)代雷達發(fā)展的

2、一個重要方向。本文針對三種具有輔助陣列的陣列結(jié)構(gòu)分別研究了窄帶ADBF和寬帶空時自適應(yīng)處理（space-time adaptive processing, STAP）方法，并給出了相應(yīng)的波束形成及性能分析。首先給出了子陣級廣義旁瓣對消器（GSLC）結(jié)構(gòu)的窄帶ADBF三種實現(xiàn)算法：Wiener-Hopf方程方法、Nickel的常規(guī)方法、Householder變換方法。在陣列誤差條件下，GSLC能有效保持波束形狀和自適應(yīng)性能，并且采用均勻子陣劃分和歸一化方法可以得到與靜態(tài)方向圖一致的旁瓣電平。接著針對寬帶信號和寬帶干擾，給出了GSLC的子陣級STAP方法，依然采用上述三種方法實現(xiàn)。然后針對子陣級S

3、LC結(jié)構(gòu)，給出ADBF與STAP實現(xiàn)算法：基于Wiener-Hopf方程方法和HA算法。子陣級主陣列用于形成靜態(tài)和波束，而陣元級輔助陣列用于自適應(yīng)抑制干擾。最后對子陣級旁瓣消除器（SLC）的STAP結(jié)構(gòu)加以改進，在輔助陣列采用子陣級處理，并使輔助陣列遠離主陣列，降低軟硬件成本的同時也提高了抑制寬帶主瓣干擾的性能。給出了基于最小方差準(zhǔn)則的方法和HA算法兩種實現(xiàn)方法。對所提出的各種方法進行了仿真，結(jié)果證明所提出的方法是有效的。關(guān)鍵詞自適應(yīng)波束形成，干擾抑制，STAP，寬帶干擾，子陣級相控陣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不要刪除行尾的分節(jié)符，此行不會被打印- 4 -目 錄摘要IAbstractII第1章 緒論11.1 課題來源及研究的目的和意義11.2 國內(nèi)外在該方向的研究現(xiàn)狀及分析41.3 論文結(jié)構(gòu)安排6第2章 基于GSLC的子陣級ADBF方法82.1 引言82.2 子陣級DSW結(jié)構(gòu)82.2.1 子陣級信號模型82.2.2 基于LCMV的DSW方法102.3 子陣級GSLC結(jié)

12、構(gòu)及其原理112.3.1 基于Wiener-Hopf的GSLC122.3.2 常規(guī)的子陣級GSLC132.3.3 基于Householder變換的子陣級GSLC152.3.4 仿真結(jié)果及分析162.4 歸一化子陣級GSLC202.4.1 重疊法原理202.4.2 歸一化原理212.4.3 仿真結(jié)果及分析222.5 本章小結(jié)23第3章 基于GSLC的子陣級STAP方法243.1 引言243.2 寬帶信號模型243.3 寬帶陣列結(jié)構(gòu)263.4 子陣級STAP方法283.4.1 信號模型293.4.2 Wiener-Hopf方法的STAP313.4.3 常規(guī)方法的STAP313.4.4 Householder變換方法的STAP323.5 仿真結(jié)果及分析333.6 本章小結(jié)35第4章 基于SLC結(jié)構(gòu)的子陣級STAP方法374.1 引言374.2 子陣級SLC的ADBF374.2.1 陣列模型374.2.2 Wiener-Hopf方法384.2.3 HA算法394.2.4 輸出SINR414.2.5 仿真結(jié)果及分析414.3 ST