Massive MIMO for Next Generation Wireless Systems
Massive MIMO for Next Generation Wireless Systems
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DOI：
10.1109/mcom.2014.6736761
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发表时间：
2014-02-01
影响因子：
11.2
通讯作者：
Marzetta, Thomas L.
中科院分区：
文献类型：
--
作者：
Larsson, Erik G.;Edfors, Ove;Marzetta, Thomas L.
多用户MIMO相比传统的点对点MIMO具有很大优势：它可与廉价的单天线终端配合使用，不需要丰富的散射环境，并且由于每个激活终端都利用所有的时频单元，资源分配得以简化。然而，最初设想的服务天线数量和终端数量大致相等且采用频分双工操作的多用户MIMO并不是一种可扩展的技术。大规模MIMO（也称为大规模天线系统、超大MIMO、超MIMO、全维度MIMO和ARGOS）通过使用比激活终端多得多的服务天线以及时分双工操作，与当前的实践彻底决裂。额外的天线通过将能量聚焦到更小的空间区域来提高吞吐量和辐射能效，从而起到帮助作用。大规模MIMO的其他优点包括大量使用廉价的低功率组件、降低延迟、简化MAC层以及对有意干扰具有鲁棒性。预期的吞吐量取决于传播环境为终端提供渐近正交的信道，但到目前为止的实验尚未揭示这方面的任何限制。虽然大规模MIMO使许多传统研究问题变得无关紧要，但它也揭示了一些亟待关注的全新问题：制造许多能有效协同工作的低成本低精度组件的挑战、新加入终端的获取和同步问题、利用过多服务天线所提供的额外自由度、降低内部功耗以实现总能效降低以及寻找新的部署场景。本文概述了大规模MIMO概念以及关于该主题的当代研究。
Multi-user MIMO offers big advantages over conventional point-to-point MIMO: it works with cheap single-antenna terminals, a rich scattering environment is not required, and resource allocation is simplified because every active terminal utilizes all of the time-frequency bins. However, multi-user MIMO, as originally envisioned, with roughly equal numbers of service antennas and terminals and frequency-division duplex operation, is not a scalable technology. Massive MIMO (also known as large-scale antenna systems, very large MIMO, hyper MIMO, full-dimension MIMO, and ARGOS) makes a clean break with current practice through the use of a large excess of service antennas over active terminals and time-division duplex operation. Extra antennas help by focusing energy into ever smaller regions of space to bring huge improvements in throughput and radiated energy efficiency. Other benefits of massive MIMO include extensive use of inexpensive low-power components, reduced latency, simplification of the MAC layer, and robustness against intentional jamming. The anticipated throughput depends on the propagation environment providing asymptotically orthogonal channels to the terminals, but so far experiments have not disclosed any limitations in this regard. While massive MIMO renders many traditional research problems irrelevant, it uncovers entirely new problems that urgently need attention: the challenge of making many low-cost low-precision components that work effectively together, acquisition and synchronization for newly joined terminals, the exploitation of extra degrees of freedom provided by the excess of service antennas, reducing internal power consumption to achieve total energy efficiency reductions, and finding new deployment scenarios. This article presents an overview of the massive MIMO concept and contemporary research on the topic.