大规模天线波束赋形的到达角估计研究

发布时间：2018-02-24 16:06

本文关键词： 到达角估计大规模天线阵列波束赋形阵列分辨率酉ESPRIT　出处：《北京交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：大规模多输入多输出(Massive Multiple Input Multiple Output,大规模 MIMO)技术是未来第五代移动通信系统的候选技术之一。通过波束赋形技术在发射端对数据进行先加权后发送的操作,使得大规模MIMO形成窄的发射波束,将主要能量对准在接收端的目标用户,提升频谱资源的复用能力和各用户的频谱效率。成功进行波束赋形技术的关键之一是获得精确的信源到达角信息。然而,当基站的天线部署从MIMO转变成大规模MIMO的过程中,对到达角信息进行精确估计的算法提出了新的挑战。尽管现存有多种方法可以进行到达角估计,但采用的研究模型大多限于均匀线阵或简单的矩形阵列、环形阵列。在大规模天线阵列系统的场景下,对二维到达角估计的研究仍存有较大空白。本文针对大规模天线阵列系统,提出了适用于波束赋形技术的到达角估计算法,可以进行俯仰角-方位角的二维联合估计,算法具有低复杂度、高估计精度的特点。本文的主要创新点归纳如下:针对三种大规模天线阵列阵型进行了系统建模,并对不同阵型的覆盖能力和角度分辨能力进行了比较分析。研究了大规模天线波束赋形技术呈现出的新特性:定向波束维度扩展和波束分辨能力提高。通过对形成最佳权向量的三种约束准则的推导,阐明了波束赋形技术和到达角估计的关系。针对波束赋形技术中的到达角估计,研究了两类估计算法:多重信号分类算法(Multiple Signal Classification,MUSIC)和借助旋转不变性的信号参数估计技术(Estimation of Signal Parameters via Rotational Invariance Techniques,ESPRIT)。借助数学理论推导和实际室内测量数据,对算法进行性能评估并提出大规模阵列波束赋形中到达角估计算法的设计准则。针对大规模均匀矩形阵列,采用酉EPSRIT算法实现俯仰角和方位角的二维联合估计。因为算法具有高精度、低复杂度、去相干、对二维角度自动配对等优点,使到达角的估计性能在大规模天线阵下的表现十分优异。利用蒙特卡洛仿真实验,深入研究了天线阵型、信源数量和阵元数目对算法性能的影响。根据性能分析,在大规模天线阵列中,方位角比俯仰角更容易受到天线阵型的影响。提出以阵列分辨率为准则分析俯仰角和方位角在角度估计性能上出现的差异,并通过理论推导进行量化表达。最后,借助对到达角估计特性的研究,为大规模天线阵列的部署设计提出了可行的方案。
[Abstract]:Large-scale Multiple Input Multiple output (Mimo) technology is one of the candidate technologies for future fifth-generation mobile communication systems. This allows the large-scale MIMO to form a narrow transmit beam, focusing the main energy on the target user at the receiving end. One of the keys to the successful beamforming technology is to obtain accurate source angle of arrival information. However, when the antenna deployment of the base station changes from MIMO to large-scale MIMO, one of the keys is to improve the multiplexing ability of spectrum resources and the spectrum efficiency of each user. The algorithm for accurate estimation of angle of arrival information presents a new challenge. Although there are many methods to estimate the angle of arrival, most of the research models used are limited to uniform linear arrays or simple rectangular arrays. Ring array. In the scene of large-scale antenna array system, there is still a large gap in the research of two-dimensional angle of arrival estimation. In this paper, an algorithm of angle of arrival estimation suitable for beamforming technology is proposed for large-scale antenna array system. Two dimensional joint estimation of pitch angle and azimuth angle can be carried out. The algorithm has the characteristics of low complexity and high estimation accuracy. The main innovations of this paper are summarized as follows: three kinds of large-scale antenna array arrays are systematically modeled. The coverage and angular resolution of different formations are compared and analyzed. The new characteristics of large scale antenna beamforming technology are studied: directional beam dimensionality expansion and beam resolution improvement. The derivation of three kinds of constraint criteria for the optimal weight vector, The relationship between beamforming technique and angle of arrival estimation is clarified. Two kinds of estimation algorithms are studied in this paper: multiple Signal classification algorithm and signal parameter estimation of Signal Parameters via Rotational Invariance estimation technique. The performance of the algorithm is evaluated and the design criteria of angle of arrival estimation algorithm in large scale array beamforming are proposed. The joint estimation of pitch angle and azimuth angle is realized by using unitary EPSRIT algorithm, because the algorithm has the advantages of high accuracy, low complexity, de-coherence, automatic pairing of two-dimensional angle, etc. The estimation performance of the angle of arrival is very good under the large-scale antenna array. The effects of antenna formation, number of sources and number of elements on the performance of the algorithm are studied by Monte Carlo simulation. In large scale antenna arrays, azimuth is more likely to be affected by antenna array than pitch angle than pitch angle. The difference between pitch angle and azimuth angle in angle estimation is analyzed using array resolution as the criterion. Finally, with the help of the research on the characteristics of angle of arrival estimation, a feasible scheme for the deployment of large antenna array is proposed.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN919.3

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