Millimeter-wave (mmWave) communication is a key technology of 5G new radio (NR) mobile communication systems. Efficient beamforming using a large antenna array is important to cope with the significant path loss experienced in the mmWave spectrum. The existing fully digital beamforming scheme requires a separate radio frequency (RF) chain for each antenna, which results in an excessive hardware cost and consumption power. Under these circumstances, hybrid beamforming which approaches the performance of fully digital beamforming while reducing the complexity is a promising solution for the mmWave multiuser transmission. By extending the existing hybrid beamforming strategies, this paper proposes a novel architecture which effectively reduces the hardware cost and complexity for large antenna arrays. The proposed scheme includes multiple subarrays in the form of uniform planar array (UPA) which are allowed to be overlapped in the two-dimensional space. The corresponding antenna structure is referred to as the two-dimensional overlapped partially connected (2D-OPC) subarray structure. We evaluate the performance of the proposed scheme to suggest performance-complexity trade-offs in designing versatile antenna arrays for efficient beamforming over the mmWave channel.

中文翻译：

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用于在稀疏毫米波信道上进行高效混合波束成形的 2D-OPC 子阵列结构

毫米波 (mmWave) 通信是 5G 新无线电 (NR) 移动通信系统的关键技术。使用大型天线阵列的高效波束成形对于应对毫米波频谱中经历的显着路径损耗非常重要。现有的全数字波束赋形方案需要为每个天线设置单独的射频（RF）链，这导致了过多的硬件成本和功耗。在这种情况下，接近全数字波束成形性能同时降低复杂性的混合波束成形是毫米波多用户传输的有前途的解决方案。通过扩展现有的混合波束成形策略，本文提出了一种新颖的架构，可有效降低大型天线阵列的硬件成本和复杂性。所提出的方案包括以均匀平面阵列（UPA）形式存在的多个子阵列，这些子阵列允许在二维空间中重叠。相应的天线结构称为二维重叠部分连接（2D-OPC）子阵列结构。我们评估了所提出方案的性能，以建议在设计通用天线阵列以在毫米波信道上进行有效波束成形时的性能-复杂性权衡。