【作者】 卢丹；

【导师】 吴仁彪；

【作者基本信息】 西安电子科技大学 ， 信号与信息处理， 2013， 博士

【摘要】 全球卫星导航系统能为海、陆、空三大领域提供实时、全天候和全球性的导航服务，广泛应用于军事和民用中，已成为当代发展最快的信息产业之一。然而，由于接收到的卫星信号淹没在噪声中，很容易受到各种有意和无意射频干扰的影响。当干扰功率超出了扩频增益所能处理的门限时，导航接收机将失锁，从而无法提供导航服务。本文对基于天线阵列的稳健的卫星导航抗干扰技术进行了系统的研究，所取得的主要研究成果为：1.研究了多类干扰共存时的抑制技术。针对同时存在的欺骗式干扰、压制式干扰、卫星多径信号干扰，提出了一种基于卫星信号来向已知的通用的多类干扰抑制算法。首先分析欺骗式干扰和卫星信号之间的相关性，根据不同的相关性采用相应的干扰子空间估计方法，然后通过向干扰正交补空间投影抑制干扰，最后利用低副瓣常规波束形成技术减少卫星多径干扰信号，同时使天线方向图主瓣指向卫星信号方向。新算法对干扰类型要求稳健，仿真数据验证了算法的有效性。2.研究了基于卫星信号来向估计的自适应抗干扰算法。首先利用干扰正交补空间投影技术抑制干扰，然后根据扩频码具有周期重复的特点，对阵列投影后数据和周期延迟数据的互相关矢量采用CLEAN算法估计卫星信号来向，最后，利用估计的卫星信号来向进行波束形成。该方法解决了直接利用扩频码周期重复特性进行干扰抑制无法满足定位要求的问题，在阵元数小于卫星信号数的情况下也能工作，因而较稳健。仿真数据和实测数据验证了算法的有效性。3.研究了盲自适应抗干扰技术，提出了基于卫星信号特点的新的空域解重扩算法并扩展到空时域。该算法也可根据需要估计出卫星信号来向信息，因此，在空时自适应处理中可直接提供均衡算法所需要的卫星信号来向信息。新算法先利用子空间投影技术进行干扰抑制，再对投影后参考天线的信号进行捕获、跟踪并重扩卫星信号，利用重扩后的信号和投影后信号的互相关矢量对阵列进行加权，因而和接收机紧密耦合，较易工程实现。新算法不必估计卫星信号来向，对卫星信号源数和阵列误差不太敏感，因而更稳健。仿真数据和实测数据验证了算法的有效性。4.研究了高动态抗干扰算法。由于传统自适应波束形成技术形成的零陷太窄，无法跟踪高动态环境下干扰方向的快速变化。因此，联合零陷加宽和稳健波束形成技术，提出了一种稳健的宽零陷高动态抗干扰算法。新算法可以提高高动态环境中小快拍数下传统零陷加宽算法的性能和稳健性。仿真数据验证了算法的有效性。更多还原

【Abstract】 Global navigation satellite system could provide real-time, all-weather and globalnavigation services for land, sea and air, which has been widely used in civil andmilitary applications and has been become one of the fastest developing informationindustries. However, the receiver is extremely vulnerable to intentional andunintentional radio frequency interferences because the received satellite signal is farlower than the noise. When the power of interference exceeds the spreading gain offeredvia the global navigation satellite system, the receiver will be unlock the satellite signal,which lost its ability to navigate. This dissertation is mainly concerned with the robustanti-jamming techniques for satellite navigation based on the array antenna. Theauthor’s major contributions are outlined as follows:1. The suppression technique for multiple kinds of interference coexistence hasbeen studied. A unified anti-jamming algorithm for deception interference, blanketjamming and satellite multipath interference is proposed based on the known thedirection of arrival (DOA) of satellite signal. Firstly, the correlation property of GPSsignal and deception interference is analyzed and the corresponding method is appliedto estimate interference subspace according to the different correlation property.Secondly, the interferences are canceled by projecting the received signal onto theinterference orthogonal complement space. Finally, satellite multipath interference ismitigated by low sidelobe conventional beamforming and also the mainlobe of the beampattern is aimed to the direction of the satellite signal. The proposed algorithm is robustfor the type of interference and simulation results show the effectiveness of the newmethod.2. The adaptive anti-jamming algorithm based on the DOA estimation has beenstudied. Firstly, the interferences are suppressed by projecting onto the interferenceorthogonal complement space. Then, according to the period repetitive property ofspread code, the cross-correlation vector between the projected data and the perioddelay data is used to estimate the directions of the satellite signals by CLEAN algorithm.Finally, the multi-beam is formed by estimated directions. The proposed algorithmcould solve the problem that interference suppression algorithm by using directly theperiod repetitive property can not satisfy the requirement of position. And the newmethod will also work well even if the number of array elements is less than the numberof GPS signals, therefore it is robust for the number of satellites. Test data andsimulation results show the effectiveness of the new algorithm. 3. The blind adaptive anti-jamming technique has been studied. The new de-spreadre-spread algorithm based on the characteristic of satellite signal is proposed. The newmethod is firstly discussed in the spatial processing, and then extended to space-timeadaptive processing. The proposed algorithm could also estimate the directions ofsatellite signal. Therefore it provides directly the direction information of equalizationrequirement in space-time processing. Firstly, the interferences are suppressed byprojecting onto the interference orthogonal complement space. Then requisition andtracking are performed for the signal of projected reference antenna, and the satellitesignal is reconstructed by tracking result. Finally, the array weight vector is calculatedby the cross-correlation vector between the reconstructed satellite signal and theprojected signal. Therefore, the new algorithm is tight coupling to the conventionalreceiver and is easy for engineer realization. The new method is not need to estimateDOAs of satellite signals and is robust because the proposed method is not sensitive forthe number of satellite signals and array error. Test data and simulation results show theeffectiveness of the proposed algorithm.4. High dynamic GPS interference suppression algorithm has been studied. In highdynamic environment, the conventional adaptive beamforming technique could nottrack the rapid change of interference directions due to the narrow nulls. Therefore, arobust widenull algorithm is proposed combing the null broadening technique withrobust beamforming technique. The new method could improve the performance androbustness of the conventional null broadening beamformer for snapshot deficient inhigh dynamic environment. Simulation results have demonstrated the performance ofthe new method.更多还原