【作者】 刘昕彤；

【导师】 吴长奇；

【作者基本信息】 燕山大学 ， 信号与信息处理， 2010， 硕士

【摘要】 波达方向估计是阵列信号处理的重要内容之一,随着通信技术和数字信号的发展,使得它在许多领域具有广泛而重要的应用价值。为了提高算法的性能,前人提出很多算法的改进。但是这些改进都会提高算法的复杂度,导致计算量增大。因此本文主要分析阵列孔径对定位算法性能的影响,以及两种通过增大阵列孔径提高算法性能的方法,具体工作如下:首先,研究了阵列模型及各种结构下的阵列接收的信号模型。讨论了多重信号子空间(MUSIC)算法,分析了阵列孔径对定位算法性能的影响。得出不需要对算法进行改进只需增大阵列孔径就可以提高算法性能的结果。其次,针对增加阵元个数给定位算法带来过大运算量的问题,使用了一种基于波束域高分辨定位的方法。该方法将信号的处理由阵元域转换到波束域,降低了协方差矩阵的维数,进而减少运算量。通过仿真分析可知与阵元域高分辨定位方法相比,该方法计算简单,运算量小,而且算法性能更好。最后,针对阵元间距超过信号波长一半时算法失效的问题,提出了一种适合宽带信号的聚焦频率选择方法。该方法不仅能够通过增大阵列孔径来提高DOA估计算法的精度而且还消除了阵元间距对DOA估计算法的限制,在没有增加算法运算量的同时充分利用了宽带信号的频率范围。通过Matlab仿真验证了算法的可行性。更多还原

【Abstract】 Direction-of-Arrival is one of the most important contents of array signal processing. With the development of communication technology, it has been applied widely in many different fields. In order to improve the performance of algorithm, a lot of reformations have been proposed. However, all these reformations will increase the complexity of algorithm and the amount of calculation. Therefore this article will mainly analyze the influence of array aperture on the performance of localized algorithm and two kinds of methods by which algorithm performance can be improved through the way of augmenting array aperture. The specific work is as follows:Firstly, array model and signal models of receiving arrays under all kinds of structures is discussed. The Multiple Signal Subspace (MUSIC) algorithm is considered. The influence of array aperture on the performance of localized algorithm is analyzed. The conclusion is that the algorithm performance can be improved by only augmenting array aperture without reforming algorithm itself.Secondly, to deal with the problem of too much amount of calculation caused by adding array elements, the location method based on beam space high resolution will transfer the algorithm process from array element space to beam space. The dimension of the covariance matrix is lowered and the amount of calculation is reduced. Through analysis we know that compared with array region high resolution, this method has simpler and less amount of calculation as well as better algorithm performance.At last, to deal with the problem that algorithm fails when space between array elements is longer than half signal wavelength; a method of Focus Frequency Selection which is suitable for broadband signal is raised. This method can not only improve the precision of DOA estimation algorithm through augmenting array aperture but also eliminate the restriction of DOA estimation algorithm caused by array space and make the most use of broadband frequency without adding any amount of algorithm calculation.The feasibility of the algorithm has been verified by Matlab Simulations.更多还原