大规模MIMO多天线系统信道信息获取与预编码技术研究

发布时间：2019-06-18 22:07

【摘要】：随着移动互联网和大数据时代的到来,人们对获得信息的速度和质量提出了越来越高的要求。大规模MIMO多天线技术以其高频谱利用效率和能量利用效率的优势获得广泛关注。本文研究了大规模MIMO系统中的信道状态信息获取技术和下行链路预编码技术。首先,本文介绍了传统MIMO多天线技术和大规模MIMO多天线技术的基本原理。综述了传统MIMO系统和大规模MIMO系统中信道估计和下行链路预编码技术。其次,本文重点分析研究大规模MIMO系统的容量,推导了单用户大规模MIMO系统和多用户大规模MIMO系统的渐进可达速率表达式。本文讨论了无协作多小区大规模MIMO系统中存在的导频污染现象,并通过理论分析和计算机仿真证明无协作多小区大规模MIMO系统是干扰受限的系统。然后,本文研究了频分双工大规模MIMO系统下行链路信道状态信息获取技术,推导了不同估计准则下的最优训练序列结构。通过利用信道空间相关性降低信道训练序列的资源开销,本文提出了一种下行链路的训练序列设计方案,并推导了训练序列的最优结构和最优长度。计算机仿真结果表明本文提出的训练序列设计方案在信道估计准确性和系统可达速率之间取得折中。最后,本文研究了大规模MIMO系统下行链路中的线性预编码和非线性预编码技术。通过计算机仿真评估了线性预编码的用户可达速率、频谱效率和能量效率等性能指标。本文应用格基约减对矢量预编码进行了改进,提出了LR-ZF-VP和LR-MMSE-VP两种预编码方案。论文在对LR-ZF-VP算法进行修正的基础上,提出了一种LR-ZF-TVP预编码方案,在系统性能和运算复杂度之间取得了较好平衡。
[Abstract]:With the arrival of the mobile Internet and the large data age, people have made more and more demands on the speed and quality of obtaining the information. The large-scale MIMO multi-antenna technology is widely concerned with the advantages of high frequency spectrum utilization efficiency and energy utilization efficiency. In this paper, the channel state information acquisition technique and the downlink precoding technique in a large-scale MIMO system are studied. First, this paper introduces the basic principle of the traditional MIMO multi-antenna technology and the large-scale MIMO multi-antenna technology. In this paper, the channel estimation and the downlink precoding technique in the traditional MIMO system and the large-scale MIMO system are summarized. Secondly, this paper analyzes the capacity of large-scale MIMO system, and derives the asymptotic rate expression of single-user large-scale MIMO system and multi-user large-scale MIMO system. In this paper, the phenomenon of pilot pollution in a non-cooperative multi-cell large-scale MIMO system is discussed, and theoretical analysis and computer simulation show that the non-cooperative multi-cell large-scale MIMO system is an interference-limited system. Then, the information acquisition technology of the downlink channel state of the frequency division duplex large-scale MIMO system is studied, and the optimal training sequence structure under different estimation criteria is derived. By using the channel space correlation to reduce the resource cost of the channel training sequence, a scheme of the downlink training sequence is proposed, and the optimal structure and the optimal length of the training sequence are derived. The computer simulation results show that the proposed scheme is a compromise between the channel estimation accuracy and the system reachable rate. In the end, this paper studies the linear precoding and the non-linear precoding technique in the downlink of the large-scale MIMO system. The performance indexes of the user-accessible rate, spectral efficiency and energy efficiency of the linear pre-coding are evaluated by computer simulation. In this paper, the pre-coding of vector pre-coding is improved, and two kinds of pre-coding schemes of LR-ZF-VP and LR-MMSE-VP are proposed. On the basis of the modification of the LR-ZF-VP algorithm, a LR-ZF-TVP pre-coding scheme is proposed, and a good balance is obtained between the system performance and the operation complexity.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN919.3

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