For wireless communications using linear large-scale antenna arrays, we define a receiving coordinate system and parameterization strategy to facilitate the study of the impact of three-dimensional position and rotation of the arrays on the achievable spatial degrees of freedom (DoF) in line-of-sight (LOS) channels. An analytical framework based on spatial bandwidth analysis is developed, under which three elementary problems corresponding to three basic orthogonal receiving directions are investigated. For each of them, accurate, simple, and interpretable closed-form approximations for the achievable spatial DoF are derived, and the spatial region where a sufficient amount of spatial DoF is expected available is determined. The expressions can easily be integrated into large-scale system-level simulations. Some interesting and surprising observations are made from simulation studies based on the analytical results. For instance, the spatial bandwidth is shown to be approximately constant in almost the entire spatial multiplexing region. Moreover, in significant parts of this region, the optimal receive array orientation is not parallel with the transmitting array.

中文翻译：

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3D 线性大规模天线阵列通信的自由度 - 空间带宽方法


对于使用线性大规模天线阵列的无线通信，我们定义了接收坐标系和参数化策略，以方便研究阵列的三维位置和旋转对线性中可实现的空间自由度（DoF）的影响。视距 (LOS) 频道。建立了基于空间带宽分析的分析框架，在该框架下研究了对应于三个基本正交接收方向的三个基本问题。对于它们中的每一个，都导出了可实现的空间 DoF 的准确、简单且可解释的封闭形式近似，并确定了预期有足够量的空间 DoF 可用的空间区域。这些表达式可以轻松集成到大规模系统级仿真中。基于分析结果的模拟研究得出了一些有趣且令人惊讶的观察结果。例如，空间带宽在几乎整个空间复用区域中显示为近似恒定。此外，在该区域的重要部分中，最佳接收阵列方向不与发射阵列平行。