Spatial Characterization of Electromagnetic Random Channels
Spatial Characterization of Electromagnetic Random Channels
复制标题
电磁随机通道的空间表征
DOI：
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发表时间：
2021
影响因子：
7.9
通讯作者：
T. Marzetta
中科院分区：
文献类型：
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作者：
Andrea Pizzo;L. Sanguinetti;T. Marzetta
大多数随机信道模型依赖于电磁远场假设，该假设允许将信道分解为平面波。远场假设在未来推向电磁近场区域的应用中被打破，例如那些设想使用电磁大型天线阵列的应用。出于这种考虑，我们展示了如何使用物理原理来导出在电抗近场区域中也有效的平面波标量通道模型。准确地说，我们表明，通过三维散射介质的窄带波传播通常可以建模为线性和空间变化的系统。我们首先回顾导致通道脉冲响应的封闭形式确定性平面波表示的物理原理。这是根据空间静态随机传播环境的统计独立高斯随机系数导出信道随机表示的基础。通过排除紧邻源的反应传播机制，可以在辐射近场区域中始终保留非常理想的空间静止特性。值得注意的是，所提供的随机表示直接连接到一般平稳空间随机场的傅里叶谱表示。
The majority of stochastic channel models rely on the electromagnetic far-field assumption, which allows to decompose the channel in terms of plane waves. The far-field assumption breaks down in future applications that push towards the electromagnetic near-field region, such as those where the use of electromagnetically large antenna arrays is envisioned. Motivated by this consideration, we show how physical principles can be used to derive a plane-wave scalar channel model that is also valid in the reactive near-field region. Precisely, we show that narrowband wave propagation through a three-dimensional scattered medium can be generally modeled as a linear and space-variant system. We first review the physics principles that lead to a closed-form deterministic plane-wave representation of the channel impulse response. This serves as a basis for deriving a stochastic representation of the channel in terms of statistically independent Gaussian random coefficients for spatially stationary random propagation environments. The very desirable property of spatial stationarity can always be retained in the radiative near-field region by excluding reactive propagation mechanisms confined in close proximity to the source. Remarkably, the provided stochastic representation is directly connected to the Fourier spectral representation of a general stationary spatial random field.