4G系统中的波束成形算法研究

发布时间：2018-04-14 17:22

本文选题：4G + 波束成形　；参考：《南京邮电大学》2015年硕士论文

【摘要】：在无线通信技术领域中,智能天线技术带来的优势目前来讲几乎是不可替代的。因此智能天线技术是无线通信领域中的研究热点,是一个最活跃的领域。近年来取得了极大的发展。而波束成形技术则是智能天线技术中非常重要的一环,其核心是将发送信号的主要能量对准期望用户,达到提高信噪比的目的。波束成形技术应运而生。而算法是波束成形技术的核心,本文就是4G LTE为背景,以波束成形算法为核心进行了研究与探讨。针对波束成形系统中阵列信号进行了模型建立,区分了理想状况下和存在误差状况下的不同,同时讨论了阵列信号的统计模型建立方法。然后围绕LTE系统展开研究,重点分析了下行链路的工作原理,解释了LTE系统的帧以及时隙是如何构成的;同时学习并研究了LTE下行物理信道中一般信号的处理过程,并且重点研究了波束成形算法中关于加权矢量的几种计算方法,对基于QR分解和基于SVD分解的算法进行了详细的分析与推导,在对其研究的基础上,综合了对角加载的原理,对对角加载的QR分解算法和SVD分解算法进行了验证。最后引入了多流波束成形算法的概念,根据单流和双流波束成形的原理进行了一系列计算与分析,进一步研究之后提出了一种基于最大化信道容量的自适应流数选择波束成形方案,并进行了仿真分析,得出了如下结论:信噪比不同的情况下,多流波束成形的性能也会随之变化,通过自适应算法可以实现自动切换流数以达到该信噪比条件下的最大信道容量。
[Abstract]:In the field of wireless communication, the advantages of smart antenna technology are almost irreplaceable.Therefore, smart antenna technology is one of the most active research fields in wireless communication field.Great progress has been made in recent years.Beamforming technology is a very important part of smart antenna technology. The core of beamforming technology is to target the main energy of the transmitted signal at the desired user to improve the signal-to-noise ratio (SNR).Beamforming technology emerged as the times require.The algorithm is the core of beamforming technology. In this paper, 4G LTE is the background, and the core of beamforming algorithm is studied and discussed.The model of array signal in beamforming system is established, and the difference between ideal condition and error condition is distinguished. At the same time, the statistical modeling method of array signal is discussed.Then the research is carried out around the LTE system, the working principle of downlink is analyzed, the frame and time slot of LTE system are explained, and the general signal processing process in the downlink physical channel of LTE is studied and studied.Several calculation methods about weighted vector in beamforming algorithm are studied, and the algorithms based on QR decomposition and SVD decomposition are analyzed and deduced in detail. On the basis of the research, the principle of diagonal loading is synthesized.The diagonally loaded QR decomposition algorithm and the SVD decomposition algorithm are verified.Finally, the concept of multi-flow beamforming algorithm is introduced, and a series of calculation and analysis are carried out according to the principle of single-flow beamforming and dual-flow beamforming.After further research, an adaptive stream number selective beamforming scheme based on maximizing channel capacity is proposed, and simulation analysis is carried out. The conclusions are as follows: under different SNR,The performance of multi-stream beamforming also changes with it. The adaptive algorithm can automatically switch the number of streams to reach the maximum channel capacity under the SNR condition.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN929.53

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