发表机构
King Abdullah University of Science and Technology; University of Southampton（阿卜杜拉国王科技大学; 南安普顿大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文研究宽带混合阵列中缓解波束分裂所需的最小RF链数量，推导全连接架构的闭式解并提出子连接架构算法，发现近场RF链数量在焦距10L后收敛至远场值，且全连接架构用更少RF链但复杂度更高。
AI 中文摘要
部署大规模天线阵列将无线通信过渡到辐射近场（NF），其中球面波前使得在联合角度-距离域中实现波束聚焦成为可能。然而，大规模天线阵列的宽带波束成形在两个空间维度上都遭受波束分裂的影响。尽管全数字阵列可以消除这一缺陷，但其高昂的硬件成本和功耗促使采用配备有限数量射频（RF）链的混合阵列架构。本文研究了缓解波束分裂所需的最小RF链数量。我们推导了全连接（FC）架构中所需RF链数量的闭式表达式，并为子连接（SC）架构提出了一种算法，同时考虑了均匀线性阵列（ULA）和均匀圆形阵列（UCA）。我们的分析表明，在超过焦距10L（其中L表示孔径长度）之后，近场RF链数量收敛到其远场对应值，并仅成为角度的函数。此外，FC混合架构通过使用比SC架构更少的RF链来缓解波束分裂，尽管以增加移相器网络的复杂度为代价。
英文摘要
Deploying large antenna arrays transitions wireless communication into the radiative near-field (NF), where spherical wavefronts enable beamfocusing in the joint angle-distance domain. However, wideband beamforming with large antenna arrays suffers from beam split across both spatial dimensions. Although fully digital arrays can eliminate this impairment, their prohibitive hardware cost and power consumption motivate the adoption of hybrid array architectures equipped with a limited number of radio-frequency (RF) chains. This paper investigates the minimum number of RF chains required to mitigate the beam split. We derive closed-form expressions for the required number of RF chains in fully-connected (FC) architectures and propose an algorithm for sub-connected (SC) architectures, considering both uniform linear arrays (ULAs) and uniform circular arrays (UCAs). Our analysis reveals that beyond a focal distance of 10L, where L denotes the aperture length, the NF RF chain count converges to its far-field counterpart and becomes a function of the angle alone. Moreover, the FC hybrid architecture mitigates the beam split by using fewer RF chains than the SC architecture, albeit at the cost of increased complexity in the phase shifter network.
