摘 要高速信息化时代催生了各种各样的技术，典型代表就是智能天线技术。其中，信号到达角估计是智能天线核心技术之一，其在无线通信研究领域中占有极大地位。智能天线通过空分多址技术可以将频率信息相同的、最小时间间隔相同的用户信号区别开来，也可以使得通信容量得到成倍的扩展。当智能天线技术同他通信技术相结合可以显著提高频率资源的利用率。

智能天线技术在通信系统涉及的技术中发挥重要作用，它可以通过准确得到用户信号到达角(Angles-of-Arrivals, AOA)信息来增强无线通信系统中的测向(Direction-finding, DF)技术。本文主要研究智能天线的核心技术——到达角估计技术。86106

首先，通过绪论章节介绍信号到达角估计技术的历史背景、发展现状。

其次，简要介绍智能天线技术的相关知识，并在此基础上详细介绍到达角估计技术的基本工作原理。

然后，主要研究了信号到达角估计算法，包括四种经典算法：巴特利特到达角估计、Capon到达角估计、线性预测到达角估计和经典MUSIC到达角估计。

最后，对经典MUSIC算法、ROOT-MUSIC算法和空间平滑算法进行了深入研究和仿真实验。由仿真实验结果分析可知，与经典MUSIC算法相比，ROOT-MUSIC算法的计算量较低。在信号源相干的情况下，空间平滑MUSIC算法可以有效的实现信号源的解相干。

关键字:智能天线，到达角估计（DOA），经典MUSIC算法，ROOT-MUSIC算法，空间平滑MUSIC算法

Abstract

High-speed information age has given rise to all kinds of technologies。 Typical representative is the smart antenna technology。 The signal direction of arrival (DOA) estimation is one of the core technology of smart antenna, which occupies a great position in the field of wireless communications research。 Smart antennas based on air separation multiple access technology can distinguish users’ signal which have same frequency and time gap, and extend communication capacity exponentially and can also improve the utilization rate of frequency resources with the help of other techniques significantly。

The smart antenna technology plays an important role of the communication system。 This technology uses the information of signal angle of arrival (AOA) to enhance the direction-finding (DF) technology in the wireless communication system。 The main content of the paper is DOA estimation, which is one of the core technologies of smart antenna。

Firstly, this paper simply introduces the historical background, development in the introduction part。 

Then, this paper simply introduces the related knowledge of smart antenna technology and makes a detail introduction about the basic working principle of DOA technology。

Finally, the classical multiple signal classification (MUSIC) algorithm, ROOT - MUSIC algorithm and spatial smoothing algorithm are studied and simulated。 Known from the analysis of simulation results, ROOT-MUSIC algorithm has high complexity of computation, compared with the classical MUSIC algorithm。 Under the condition of the coherent signal source, spatial smoothing MUSIC algorithm can effectively attain solution of coherent signal source。

Keywords:  Smart Antenna, DOA estimation, MUSIC DOA estimation,  ROOT-MUSIC DOA estimation, Spatial Smoothing Algorithm 

目录

第一章 绪论 1

1。1 引言 1

1。2 DOA估计历史背景 2

1。3 DOA估计发展现状 2

1。4 本文主要内容 3

第二章 智能天线和到达角估计的基本工作原理