Energy and Spectral Efficiency of Very Large Multiuser MIMO Systems
Energy and Spectral Efficiency of Very Large Multiuser MIMO Systems
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DOI：
10.1109/tcomm.2013.020413.110848
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发表时间：
2013-04-01
影响因子：
8.3
通讯作者：
Marzetta, Thomas L.
中科院分区：
文献类型：
--
作者：
Hien Quoc Ngo;Larsson, Erik G.;Marzetta, Thomas L.
多个自主终端同时向紧凑的天线阵列发送数据流。该阵列使用从发送的导频导出的不完美的信道状态信息来提取各个数据流。可以使终端辐射的功率与基站天线数量的平方根成反比，而不降低性能。相反，如果完美的信道状态信息是可用的，则功率可以与天线的数量成反比。推导了最大比合并（MRC）、迫零（ZF）和最小均方误差（MMSE）检测的容量下限。MRC接收机通常比ZF和MMSE性能更差。然而，随着功率电平的降低，由较差的最大比接收机引入的串扰最终福尔斯噪声电平以下，并且这种简单的接收机成为可行的选择。对于包括小尺度衰落但不包括大尺度衰落的信道模型，量化能量效率（以比特/J测量）和频谱效率（以比特/信道使用/终端测量）之间的折衷。结果表明，使用适度大的天线阵列可以提高频谱和能量效率的数量级相比，一个单天线系统。
A multiplicity of autonomous terminals simultaneously transmits data streams to a compact array of antennas. The array uses imperfect channel-state information derived from transmitted pilots to extract the individual data streams. The power radiated by the terminals can be made inversely proportional to the square-root of the number of base station antennas with no reduction in performance. In contrast if perfect channel-state information were available the power could be made inversely proportional to the number of antennas. Lower capacity bounds for maximum-ratio combining (MRC), zero-forcing (ZF) and minimum mean-square error (MMSE) detection are derived. An MRC receiver normally performs worse than ZF and MMSE. However as power levels are reduced, the cross-talk introduced by the inferior maximum-ratio receiver eventually falls below the noise level and this simple receiver becomes a viable option. The tradeoff between the energy efficiency (as measured in bits/J) and spectral efficiency (as measured in bits/channel use/terminal) is quantified for a channel model that includes small-scale fading but not large-scale fading. It is shown that the use of moderately large antenna arrays can improve the spectral and energy efficiency with orders of magnitude compared to a single-antenna system.