Performance Analysis of Large Multiuser MIMO Systems With Space-Constrained 2-D Antenna Arrays
Performance Analysis of Large Multiuser MIMO Systems With Space-Constrained 2-D Antenna Arrays
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DOI：
10.1109/twc.2016.2522419
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发表时间：
2016-05
影响因子：
10.4
通讯作者：
S. Biswas;C. Masouros;T. Ratnarajah
中科院分区：
文献类型：
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作者：
S. Biswas;C. Masouros;T. Ratnarajah
大规模多输入多输出（MIMO）系统部署在基站（BS）的大量天线已被证明产生高频谱和能量效率（EE）的假设下，增加BS的物理空间和临界天线间距。我们研究了大规模MIMO系统的部署和由此产生的EE与一个更现实的情况下，考虑在一个固定的物理空间内增加天线单元的2-D矩形阵列。通过推导考虑BS内所有天线单元之间耦合的实际互耦矩阵，将BS天线之间的互耦和相关性合并。我们还提供了一个现实的能源消耗分析使用的模型，它考虑到电路功耗作为BS天线的数量的函数，然后提出了一个性能分析的两个实际的低复杂度检测器/接收器保持EE考虑。仿真结果表明，EE不单调增加的BS天线的数量。相反，它是BS天线数量的递减凹函数或准凹函数，这取决于在接收机处使用的检测技术。我们还表明，随着天线之间的间距减小，互耦增加，有助于减少EE。因此，我们的分析表明，EE不会无限增加时，在一个大规模的MIMO系统的天线数量增加被容纳在一个固定的物理空间和总功率消耗被认为是天线的函数。因此，封闭形式的表达式的天线的最佳数量，以达到最大EE的迫零（ZF）。
Massive multiple-input-multiple-output (MIMO) systems deploying a large number of antennas at the base station (BS) have been shown to produce high spectral and energy efficiency (EE) under the assumptions of increasing BS physical space and critical antenna spacing. We examine the deployment of massive MIMO systems and resulting EE with a more realistic scenario considering a 2-D rectangular array with increasing antenna elements within a fixed physical space. Mutual coupling and correlation among the BS antennas are incorporated by deriving a practical mutual coupling matrix which considers coupling among all antenna elements within a BS. We also provide a realistic analysis of the energy consumption using a model, which takes into account the circuit power consumptions as a function of the number of BS antennas and then present a performance analysis of two practical low complexity detectors/receivers keeping EE into consideration. The simulation results obtained show that EE does not monotonically increase with the number of BS antennas. On the contrary, it is a decreasing concave or quasi-concave function of the number of BS antennas depending on the detection technique used at the receiver. We also show that with decreasing spacing between the antennas, mutual coupling increases, contributing toward reduction in EE. Our analysis thus shows that EE does not increase infinitely in a massive MIMO system when the increasing number of antennas are to be accommodated within a fixed physical space and the total power consumed is considered to be a function of the antennas. Accordingly, closed-form expressions for the optimum number of antennas to attain maximum EE for zero forcing (ZF) are obtained.