文档介绍：华中科技大学
硕士学位论文
多输入多输出(MIMO)天线条件下多基站反馈技术研究
姓名:李长江
申请学位级别:硕士
专业:通信与信息系统
指导教师:黄瑞光
2011-02-21
华中科技大学硕士学位论文
摘要
在下一代移动通信系统中,P)的方法增加系统和边缘
用户的吞吐量是目前重要的研究方向。在协同多点传输技术中,多个基站可以同时
向同一边缘用户发送有用信号。另一方面,在无线 MIMO 通信系统中,用户可以向
基站反馈信道信息以提高系统性能。P 条件下如何向基站反馈信道信息以
提高系统性能,成为本文研究的主要内容。
本文首先简要回顾了了一些基础知识。介绍了多输入多输出系统的基本模型和
基本原理,预编码的概念和预编码的工作原理,LTE 系统的反馈的原理及其流程。然后
对协同多点传输系统进行了讨论和分析。而对于协同多点的情况而言,这时反馈可
以有两种方式:联合反馈和分别反馈。所谓联合反馈,是指用户反馈一个大的联合
信息反映所有基站需要的信息。而分别反馈是指用户对于每个小区分别单独的反馈
信息。联合反馈应有更好的性能,本文通过理论分析和仿真相结合的方法证明了这
一结论。
联合反馈有两种编码码本,联合码本和组合码本。虽然联合码本性能优良,但
针对多小区的情况,编码的灵活性不够。所以产生了组合式码本。这种码本由原来
各小区的码本相组合而成。我们对组合码本进行了改进,增加对时延差的反馈。并
比较了改进组合码本和组合码本的性能。通过仿真证明对码本进行改进后获得了良
好的性能提升。
关键词:预编码,反馈, ,
I
华中科技大学硕士学位论文
Abstract
For next munication system, increasing the system and cell-edge
throughput by using coordinated multi-point (COMP) transmission is of particular interest .
P, the base stations can transmit signal to a cell-edge user together. On the other
hand, in wireless munication system, the mobile station can report the channel
information to improve the system. P, how to feedback is studied on in the paper.
In the paper, the MIMO, precoding, LTE P are introduced. P the
feedback can be reported in two manners: joint report and disjoint report. Joint report
means The UE reports a single report which puted jointly for all the cells. Disjoint
report means the report puted separately for each of the cells. Joint report should be
better. And we prove this by analysis and simulation.
Joint report can be designed in two manners: Joint design and Disjoint design. Though
joint design can get more system benefit, it is not flexible enough. Then disjoint design is
introduced. The codebook is formed by mon single-cell codebooks.
And we improve disjoint design codebook by feedback time delay. pare the
improved codebook with original one by simulation and prove that the improved
codebook is better.
Key Words: precoding feedback LTE