A Coordinated Approach to Channel Estimation in Large-Scale Multiple-Antenna Systems
A Coordinated Approach to Channel Estimation in Large-Scale Multiple-Antenna Systems
复制标题
DOI：
10.1109/jsac.2013.130214
复制
发表时间：
2012-03
影响因子：
16.4
通讯作者：
Haifan Yin;D. Gesbert;Miltiades Filippou;Yingzhuang Liu
中科院分区：
文献类型：
--
作者：
Haifan Yin;D. Gesbert;Miltiades Filippou;Yingzhuang Liu
研究了多小区限制干扰蜂窝网络中的信道估计问题。我们考虑采用多天线的系统，并对有限和大规模天线数制度（所谓的“大规模MIMO”）感兴趣。这种系统通过在每个基站上应用每个小区波束形成的方式来处理多小区干扰。在这种网络中，信道估计受到导频污染效应的阻碍，构成了总体性能的主要瓶颈。我们提出了一种新的方法，通过在信道估计阶段本身实现细胞之间的低速率协调来解决这个问题。这种协调利用了额外的关于用户信道的二阶统计信息，这些信息被证明提供了一种强大的方法来区分具有强相关导频序列的干扰用户。重要的是，我们分析地证明了在大量天线的情况下，在信道协方差的某些条件下，导频污染效应可以完全消失。通过对小天线阵列的仿真，证实了该方法优于传统信道估计框架的增益。
This paper addresses the problem of channel estimation in multi-cell interference-limited cellular networks. We consider systems employing multiple antennas and are interested in both the finite and large-scale antenna number regimes (so-called "massive MIMO"). Such systems deal with the multi-cell interference by way of per-cell beamforming applied at each base station. Channel estimation in such networks, which is known to be hampered by the pilot contamination effect, constitutes a major bottleneck for overall performance. We present a novel approach which tackles this problem by enabling a low-rate coordination between cells during the channel estimation phase itself. The coordination makes use of the additional second-order statistical information about the user channels, which are shown to offer a powerful way of discriminating across interfering users with even strongly correlated pilot sequences. Importantly, we demonstrate analytically that in the large-number-of-antennas regime, the pilot contamination effect is made to vanish completely under certain conditions on the channel covariance. Gains over the conventional channel estimation framework are confirmed by our simulations for even small antenna array sizes.