Pilot pattern adaptation for 5G MU-MIMO wireless communications
Pilot pattern adaptation for 5G MU-MIMO wireless communications
复制标题
5G MU-MIMO 无线通信的导频模式自适应
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
S. Tomasin
中科院分区：
文献类型：
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作者：
N. Ksairi;B. Tomasi;S. Tomasin
为了实现频谱效率提高十倍的目标，能够实现高空间复用增益的多用户多输入多输出（MU-MIMO）技术预计将成为第五代（5G）无线接入系统的重要组成部分。通过为基站配备大量天线来实现复用增益的增加，这使得信道状态信息（CSI）获取开销成比例增加。本文通过优化为信道训练目的分配的时频资源量来解决减少 CSI 开销的问题，同时不影响相关信道估计的质量。首先，我们表明，在 MU-MIMO 中，调整时频网格中的导频符号密度应该在每个资源块 (RB) 的基础上以及在共享相似信道条件的用户组的基础上执行。接下来，我们提出了一种可以执行基于分组的每 RB 导频模式自适应的实用方案。最后，我们使用分析结果和数值结果来评估与使用固定导频模式的传统 MU-MIMO 系统相比，使用该方案可以实现的频谱效率增益。
To meet the goal of ten-fold increase in spectral efficiency, multiuser multiple-input-multiple-output (MU-MIMO) techniques capable of achieving high spatial multiplexing gains are expected to be an essential component of fifth-generation (5G) radio access systems. This increase in multiplexing gain, made possible by equipping base stations with a large number of antennas, entails a proportional increase in channel state information (CSI) acquisition overhead. This article addresses the problem of reducing this CSI overhead by optimizing the amount of time-frequency resources allocated for channel training purposes while not affecting the quality of the associated channel estimate. First we show that in MU-MIMO, adapting pilot symbol density in the time-frequency grid should be performed both on a per resource block (RB) basis and on the basis of groups of users sharing similar channel conditions. Next, we propose a practical scheme that can perform grouping based per-RB pilot pattern adaptation. Finally, we evaluate using both analytical and numerical results the gain in spectral efficiency that can be achieved using this scheme as compared to conventional MU-MIMO systems that use fixed pilot patterns.