智能天线系统中的方向调制技术研究

摘要在军事方面，随着电子干扰技术在军事领域里的迅速发展，增强现役雷达的抑制干扰能力的问题亟待解决。在民用方面，移动通信面临用户剧增和通信安全性的问题，进一步增大通信容量、提高链路传送质量和安全通信成为研究热点。智能天线系统的自适应波束形成技术、波达方向估计技术、方向调制技术等提供了解决上述问题的新思路。数字技术的发展及其在形成天线波束上的广泛应用也使得天线系统越来越可靠和灵活。
本文详细介绍分析了自适应波束形成、波达方向估计和方向调制的算法，对部分算法进行了仿真，并对比了多种算法的优缺点。首先研究了三种经典的自适应波束形成算法MVDR、LMS、RLS；其次介绍了波达方向DOA估计中的子空间方法并详细研究了超分辨的MUSIC算法及其改进算法；最后探讨了如何将遗传算法用于方向调制中，用于提供更好的基于相控阵的物理层安全通信信号。
关键词: 智能天线自适应波束形成波达方向估计方向调制安全通信19540
毕业论文设计说明书（论文）外文摘要
Title Study of direction modulation in smart antenna   systems

Abstract
With the rapid development of electronic jamming technology in the military application, it is necessary to enhance the capability of suppressing interferences for current radar system. Besides, improving capacity, quality and security are essential in mobile communication due to the increasing number and unstable security. One sees adaptive beam-forming (ABF), direction of arrival (DOA) estimation and direction modulation(DM) in smart antenna systems provide effective solutions to these problems. Moreover, recent application of digital technology in antenna beamforming makes antenna more reliable and flexible.
This thesis analyzes some algorithms for ABF, DOA estimation and DM. The simulation results are also presented in order to compare their performance. First, I study three ABF algorithms: MVDR, LMS, RLS. Second, the MUSIC algorithm, one classic super-resolution of DOA estimation subspace algorithms in DOA estimation, is extensively investigated. Finally, a discussion of how to apply genetic algorithm (GA) in DM is given to obtain that the DM signal is more safe in physical layer basing on phased array.
Key words: Smart antenna system, Adaptive beamforming, Direction of arrival estimation, Direction modulation , Secure communication
目   次
1 绪论    1
1.1 研究背景及意义    1
1.2 研究发展和现状    2
1.3 本文的主要工作    5
2 自适应波束形成的仿真研究    6
2.1 自适应波束形成    7
2.2 MVDR算法    9
2.3 LMS算法    10
2.4 RLS算法    11
2.5 本章小结    13
3 DOA估计的仿真研究    14
3.1 DOA估计的子空间法    14
3.2 改进的MUSIC算法    18
3.3 本章小结    22
4 方向调制的仿真研究    23
4.1 遗传算法    23
4.2 DM调制的GA算法    25
4.3 改进的GA算法与仿真    30
4.4 本章小结    32
结束语    32
致谢    33 智能天线系统中的方向调制技术研究:http://www.751com.cn/tongxin/lunwen_10941.html