【作者】 于波；

【导师】 杨莘元；

【作者基本信息】 哈尔滨工程大学 ， 通信与信息系统， 2004， 硕士

【摘要】 阵列信号处理已广泛应用于雷达、声纳、通信、地震勘探、射电天文、医学诊断等方面。均匀圆阵列是一种常用的阵列形式，其阵列流形矩阵比均匀线阵复杂性得多，所以基于圆阵的信号处理方法有着本身的特殊性。本文针对基于圆阵列的自适应波束形成和波达方向估计方法进行了研究，涉及的主要内容如下： 1．较为详细地介绍了圆阵列天线的阵列模型、统计模型和模式空间概念。通过利用预处理技术把均匀圆阵可以转换为模式空间的虚拟均匀线阵，本文在所研究的信号处理方法中充分利用了圆阵的这一特性； 2．结合基于特征空间的自适应波束形成算法(ESB)和圆阵模式空间概念，并把Toeplitz化技术应用于圆阵自适应波束形成中得到一种新算法，算法具有较快的收敛速度，并对相干干扰有一定的抑制作用； 3．为有效地抑制相干干扰，本文结合均匀圆阵的模式空间概念和ESB算法，提出了一种基于圆阵的波束形成新算法，该算法利用模式空间的虚拟均匀线阵进行前后向模式平滑得到权向量，然后把所得到权向量对全阵列进行波束形成。仿真表明，算法能有效地抑制相干干扰，具有明显的小快拍数收敛特性，并比常规的模式平滑算法提高了阵列孔径利用率； 4．合理地采用预处理技术可以改善波束形成的性能，阵列的平动移位在理论上相当于对阵列的一种预处理，本对基于阵列移位的自适应波束形成算法的性能进行了研究，通过对该算法在阵列存在移位误差、幅相误差和相干干扰等情况时的性能进行仿真，结果表明该算法有较好的抗干扰性能和较强的稳健性； 5．本文对基于圆阵的模式空间概念的模式平滑波达方向估计算法进行了性能仿真研究，仿真结果表明这些算法可以有效地实现对相干信源波达方向的估计。更多还原

【Abstract】 Array signal processing has been applied in a lot of aspects, such as Radar, Communication and otherwise. Due to the identity in every direction, the uniform circular array (UCA) is one of common geometrical structures. But the manifold matrix of UCA is more complicated than that of the uniform linear array (ULA) and it has its special signal processing methods. The dissertation does some research on signal processing methods based on uniform circular array antennas. The main contents of the dissertation are as follow.Firstly, the data model and statistic model of UCA are introduced. It is also introduced that UCA can be transformed into the virtual uniform linear array, and the characteristic of UCA is enough used in this dissertation.Secondly, Toeplitz technique is applied to the Eigenspace-Baced (ESB) adaptive beamforming algorithm for the mode space of UCA. By means of the Toeplitz technique this beamforming algorithm can rapidly converge.Thirdly, in order to suppress the coherent interference, the mode space smoothing adaptive beamforming algorithm is presented in this dissertation. Simulation results have strongly verified the effectiveness of the algorithm.Fourthly, another adaptive beamforming algorithm for UCA is introduced. The advantage of the algorithm is that it can keep up the array aperture when the coherent interference is suppressed. In the meantime, the simulation results also show that it can be more robust than the conventional beamforming algorithm when the practical arrays exist errors.Lastly, two methods to estimate DOAs of coherent sources impinging on UCA are introduced, and simulation results have verified the effectiveness of these algorithms.更多还原