Capacity limits of MIMO channels
Capacity limits of MIMO channels
复制标题
DOI：
10.1109/jsac.2003.810294
复制
发表时间：
2003-06-01
影响因子：
16.4
通讯作者：
Vishwanath, S
中科院分区：
文献类型：
--
作者：
Goldsmith, A;Jafar, SA;Vishwanath, S
我们提供了一个广泛的单用户和多用户多输入多输出（MIMO）信道的香农容量的最新结果的概述。虽然巨大的容量增益已被预测为这样的信道，这些预测是基于对基本的时变信道模型，以及如何以及它可以被跟踪在接收机，以及在发射机有点不切实际的假设。更现实的假设可以显著影响MIMO技术的潜在容量增益。对于时变MIMO信道，有多种香农理论容量定义，对于每种定义，我们考虑不同的相关模型和信道信息假设。我们首先提供了一个全面的总结遍历和容量与中断的结果，单用户MIMO信道。这些结果表明，从多个天线获得的容量增益在很大程度上取决于在接收机或发射机，信道信噪比，和每个天线单元上的信道增益之间的相关性的可用信道信息。然后，我们把注意力集中在多址接入信道（MAC）的容量区域和广播信道的最大已知可达到的速率区域。与单用户MIMO信道相比，即使对于恒定信道，这些多用户MIMO信道的容量结果也很难获得。We.总结了对于恒定或衰落信道的MIMO广播和MAC的结果，其中具有发射机和接收机处的天线增益的完美瞬时知识。我们表明，MIMO多址接入的容量区域和MIMO广播信道的最大已知可实现速率区域（称为脏纸区域）是密切相关的，通过一个对偶变换。该变换有助于找到在MIMO广播脏纸区域的传输策略方面实现MIMO MAC容量区域的边界上的点的传输策略，反之亦然。最后，我们讨论了多小区MIMO信道与基站合作的容量结果。然后，基站充当空间分集天线阵列，利用这种结构的传输策略表现出显着的容量增益。本节还简要讨论了与MIMO蜂窝相关的系统级问题。在这一领域的开放问题比比皆是，并在整个文件进行了讨论。
We provide an overview of the extensive recent results on the Shannon capacity of single-user and multiuser multiple-input multiple-output (MIMO) channels. Although enormous capacity gains have been predicted for such channels, these predictions are based on somewhat unrealistic assumptions about the underlying time-varying channel model and how well it can be tracked at the receiver, as well as at the transmitter. More realistic assumptions can dramatically impact the potential capacity gains of MIMO techniques. For time-varying MIMO channels there are multiple Shannon theoretic capacity definitions and, for each definition, different correlation models and channel information assumptions that we consider. We first provide a comprehensive summary of ergodic and capacity versus outage results for single-user MIMO channels. These results indicate that the capacity gain obtained from multiple antennas heavily depends on the available channel information at either the receiver or transmitter, the channel signal-to-noise ratio, and the correlation between the channel gains on each antenna element. We then focus attention on the capacity region of the multiple-access channels (MACs) and the largest known achievable rate region for the broadcast channel. In contrast to single-user MIMO channels, capacity results for these multiuser MIMO channels are quite difficult to obtain, even for constant channels. We. summarize results for the MIMO broadcast and MAC for channels that are either constant or fading with perfect instantaneous knowledge of the antenna gains at,both transmitter(s) and receiver(s). We show that the capacity region of the MIMO multiple access and the largest known achievable rate region (called the dirty-paper region) for the MIMO broadcast channel are intimately related via a duality transformation. This transformation facilitates finding the transmission strategies that achieve a point on the boundary of the MIMO MAC capacity region in terms of the transmission strategies of the MIMO broadcast dirty-paper region and vice-versa. Finally, we discuss capacity results for multicell MIMO channels with base station cooperation. The base stations then act as a spatially diverse antenna array and transmission strategies that exploit this structure exhibit significant capacity gains. This section also provides a brief discussion of system level issues associated with MIMO cellular. Open problems in this field abound and are discussed throughout the paper.