相干信号DOA估计的研究 - 图文

大连海事大学

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毕 文

相干信号DOA估计方法的研究与仿真

专业班级： 通信二班

姓 名： 雷福亮

指导教师： 李森

信息工程学院

内 容 摘 要

相干信号的DOA估计是阵列信号处理中的一个研究热点，也是阵列信号处理中的一个重要研究课题，也是雷达、声纳、通信等领域基本任务之一。为了解决相干信号的处理问题，各国学者提出了不少算法，这些算法大致可分为两类:一类以牺牲有效阵元数来换取信号的不相关性，即先对阵列信号进行去相干的预处理，而后应用普通的各种算法以获取精确的到达角，如空间平滑法，前后向预测投影矩阵法，数据矩阵分解法。另一类是不损失阵列孔径而利用移动阵列的方法或采用频率平滑法处理相干信号。

本文重点是关于相干信号DOA估计算法的研究。首先介绍了DOA估计问题的原理，对部分非相干信号DOA估计的经典算法进行了分析与比较。之后重点研究了解决相干信号DOA估计的前向空间平滑算法和前后向空间平滑算法。最后通过MATLAB仿真验证了以上算法的有效性。

关键词:相干信号DOA估计；阵列信号处理;空间平滑。

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Abstract

The DOA(Direction-of-Arrival) estimation of coherent signals is a research hotspot and important research subject of array signal processing, it is also one of the basic task of radar, sonar communication areas and so on. In order to solve the problem of the DOA estimation of coherent signals, researchers all over the world proposed a lot of algorithms, all the algorithms can be departed two types: he first type can decrease the relativity of coherent signals by sacrificing the number of arrays, that is preprocessing the coherent signals then estimate the precise DOA with the common algorithms such as the spatial smoothing, forward backward prediction projection and data matrix decomposition algorithm. The other type needn't decrease the aperture of the arrays, which shift the arrays or make use of frequency smoothing to decrease the relativity.

This dissertation put the emphasis on researches of direction-of-arrival estimation algorithms. It first introduces the principles of DOA estimation, and makes analysis and comparison about the classical algorithms of the DOA estimation of incoherent signal. And then, it puts the emphasis on researching to resolve the front space smooth algorithm and front-rear space smooth algorithm of DOA estimation of coherent signals. At last, through MATLAB simulation prove the efficiency of the algorithm.

Keywords: DOA estimation of coherent signals ; Signal Processing; space smooth

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目 录

1 绪论························································································································································ 1

1.1 课题研究背景及意义················································································································· 1 1.1.1 阵列信号处理·····························································································································1 1.1.2 高分辨波达方向估计················································································································ 1 1.1.3 相干信源DOA估计技术的国内外研究现状··········································································2 2 阵列信号处理模型·································································································································2

2.1 空间谱估计的系统结构················································································································2 2.2窄带信号源数学模型·····················································································································3 2.3相干信号源数学模型·····················································································································5 3 波达方向估计的算法研究·····················································································································6

3.1 DOA估计的传统法··························································································································6 3.1.1 延迟－相加法·····························································································································6 3.1.2 Capon最小方差法·······················································································································7 3.2 DOA估计的子空间法······················································································································8 3.2.1 MUSIC算法··································································································································8 4 相干信号的DOA估计·····························································································································12

4.1 基于解相干的MUSIC算法·········································································································12 4.2 空间平滑算法································································································································12 4.2.1 前向空间平滑法·······················································································································12 4.2.2 前后向空间平滑法···················································································································14

4.3 计算机仿真实验····························································································································15 5 结论与展望·············································································································································17 参考文献 致谢

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