Design and evaluation of a reconfigurable antenna array for MIMO systems
Design and evaluation of a reconfigurable antenna array for MIMO systems
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DOI：
10.1109/tap.2008.916908
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发表时间：
2008-03-01
影响因子：
5.7
通讯作者：
Dandekar, Kapil R.
中科院分区：
文献类型：
--
作者：
Piazza, Daniele;Kirsch, Nicholas J.;Dandekar, Kapil R.
提出了一种用于多输入多输出(MIMO)通信系统的新型可重构天线阵，提高了近距离天线阵的链路容量。天线系统由两个印刷偶极子组成的阵列，相隔四分之一波长的距离。可以使用PIN二极管开关重新配置每个偶极子的长度。可以以适应环境变化的方式修改交换机配置。开关的配置影响阵列单元之间的互耦合，并随后影响每个天线的辐射方向图，导致可用于提高链路容量的不同程度的方向图分集。首先通过对集群MIMO信道模型中天线的容量分析，提出了基于PIN二极管的可重构天线解决方案。引入了空间相关系数的新定义，在量化方向图分集的收益时，考虑了天线失配和辐射效率的影响。接下来，通过在室外和室内环境中的计算电磁模拟和在室内实验室环境中的现场测量，证明了相对于传统的半波长印刷偶极子，所提出的技术具有广泛的适用性。结果表明，对于本文所考虑的2×2系统，与采用不可重构天线阵列的系统相比，在室内环境中，在信噪比(SNR)分别为10d B和20d B的情况下，链路容量分别获得了10%和8%的平均改善。
New reconfigurable antenna array is demonstrated for multiple input multiple output (MIMO) communication systems that improves link capacity in closely spaced antenna arrays. The antenna system consists of an array of two printed dipoles separated by a distance of a quarter wavelength. Each of the dipoles can be reconfigured in length using PIN diode switches. The switch configuration can be modified in a manner adaptive to changes in the environment. The configuration of switches effects the mutual coupling between the array elements, and subsequently, the radiation pattern of each antenna, leading to different degrees of pattern diversity which can be used to improve link capacity. The PIN diode-based reconfigurable antenna solution is first motivated through a capacity analysis of the antenna in a clustered MIMO channel model. A new definition of spatial correlation coefficient is introduced to include the effects of antenna mismatch and radiation efficiency when quantifying the benefit (of pattern diversity. Next, the widespread applicability of the proposed technique is demonstrated, relative to conventional half wavelength printed dipoles, using computational electromagnetic simulation in an outdoor and indoor environment and field measurements in an indoor laboratory environment. It is shown for the 2 X 2 system considered in this paper, that an average improvement or 10% and 8% is achieved in link capacity for a signal to noise ratio (SNR) respectively of 10 dB and 20 dB in an indoor environment compared to a system employing non reconfigurable antenna arrays.