On the Transmission Method for Short-Range MIMO Communication
On the Transmission Method for Short-Range MIMO Communication
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短距离MIMO通信传输方法研究
DOI：
10.1109/tvt.2011.2113196
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发表时间：
2011
影响因子：
6.8
通讯作者：
K. Hiraga
中科院分区：
文献类型：
--
作者：
K. Nishimori;N. Honma;T. Seki;K. Hiraga
本文研究了一种适用于近距离多输入多输出（MIMO）传输的传输方案。由于近程MIMO中两个阵列天线面对面的距离与阵列天线孔径大小相当，因此其传播特性与传统MIMO有很大不同。与传统MIMO不同，短距离MIMO存在使信道容量最大化的最优单元间距。此外，由于在短距离MIMO中获得了能够使信道容量最大化的最优特征值分布，因此天线间距最优的信道容量超过了独立同分布信道的遍历容量。在本文中，我们关注的是实际的传输方法，因为需要复杂的传输方案，如特征模式传输或最大似然检测来获得理想的信道容量。在考虑最优单元间距的情况下，通过接收机零强迫（ZF）获得的信道容量与使用本征模式传输获得的信道容量几乎相同。使用基于IEEE 802.11n标准的实际信号的4 × 4 MIMO测试平台，还阐明了短距离MIMO通信的有效性。仿真和实测结果表明，最优单元间距是近距离MIMO通信的关键参数。我们发现设计具有最佳单元间距的天线阵列是实现简单硬件配置的非常有效的方法。
This paper investigates a transmission scheme that is suitable for short-range multiple-input-multiple-output (MIMO) transmission. Since the distance between two array antennas that face each other is comparable with the size of the array antenna aperture in short-range MIMO, the propagation characteristics are greatly different from those in conventional MIMO. Unlike conventional MIMO, the optimal element spacing, which maximizes channel capacity, exists in short-range MIMO. Moreover, the channel capacity with optimal antenna spacing exceeds the ergodic capacity of independent identically distributed (i.i.d.) channels since optimal eigenvalue distribution, which can maximize channel capacity, is obtained in the short-range MIMO. In this paper, we focus on the actual transmission methods, because complex transmission schemes such as eigenmode transmission or maximum-likelihood detection are required to obtain ideal channel capacity. We clarify that the channel capacity obtained by zero forcing (ZF) at the receiver without beamforming at the transmitter is almost the same as that using eigenmode transmission when considering the optimal element spacing. The effectiveness of short-range MIMO communication is also clarified using a 4 × 4 MIMO testbed with actual signals based on the IEEE 802.11n standard. Simulated and measured results show that optimal element spacing is a key parameter in the short-range MIMO communication. We found that designing antenna arrays with optimal element spacing is a very effective approach to achieving a simple hardware configuration.