大规模MIMO系统中克服导频污染的传输方案研究

项目名称： 大规模MIMO系统中克服导频污染的传输方案研究

项目编号： No.61302066

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 无线电电子学、电信技术

项目作者： 范建存

作者单位： 西安交通大学

项目金额： 26万元

中文摘要： 大规模MIMO通过在基站配置大规模天线阵列，可以显著提高系统的能量效率和频谱效率，因此被认为是下一代移动通信的关键技术而受到广泛关注。在基站天线显著增加时，TDD系统因上下行信道互易而受到显著青睐，但受限于信道相干时间，此时可用的正交导频有限，以致相邻小区将不得不复用非正交导频序列而导致了导频污染。现有研究表明，导频污染已成为限制大规模MIMO系统性能的瓶颈。基于此，本申请拟对大规模MIMO系统中克服导频污染的传输方案进行研究，具体包括：1）根据导频污染主要由边缘用户产生的事实，提出了区别对待边缘和中心用户的部分导频复用方案；2）将正交导频序列看做一种资源，提出了基于动态导频分配和多用户调度的导频污染避免方案；3）基于干扰也是一种有用信号的事实，设计了一种将干扰转化为有效信号的多小区协作方案。通过这三方面研究，将有效的克服导频污染，从而推动大规模MIMO技术向实用化发展。

中文关键词： 大规模MIMO；导频污染抑制；导频复用；3D天线阵；预编码

英文摘要： Massive MIMO with a very large number of base station (BS) antennas can significantly improve system energy efficiency and spectrum efficiency. Du to these advantages, it has been considered as a key technique in future wireless communication systems. Since the large BS antennas will increase the training overhead and the difficulty of channel estimation, Time Division Duplexing (TDD) systems exploiting channel reciprocity are exploited in massive MIMO systems. Due to limited channel coherence times in TDD systems, non-orthogonal training sequences have to be utilized in different adjacent cells, which will result in serious pilot contamination problems. Pilot contamination has been viewed as a bottleneck of limiting system performance of massive MIMO. Therefore, this proposal will focuse on designing sveral effective trassmission schemes to overcome this problem. The detailed research contenents are listed as follows: 1) We will propose a partial pilot refuse scheme based on the fact that the pilot contamination is mainly dominated by the cell-edge users. 2) We will propose a dynamic pilot refuse and multiuser scheduling scheme to overcome pilot contamination. 3) We will propose a muticell cooperation scheme to transmform the inter-cell interferences introduced by pilot contamination into the available signals.

英文关键词： Massive MIMO；Pilot Contamination；Pilot Reuse；3D Antenna Array；Precoding