Conventional hybrid precoding and combining based transceivers require a large number of high-resolution radio frequency (RF) phase shifters (PSs), which impose prohibitive hardware costs and power consumption. To address the above issue, both partially connected RF PSs and low-resolution PSs have been proposed. However, the performance limits of these low-cost designs have not been investigated theoretically. Furthermore, there is room for improvement in their spectral efficiency. To fill this knowledge gap, we derive the mean square error performance discrepancy between an optimal precoder/combiner and the hybrid analog-digital precoder/combiner under the constraint of 1-bit PSs relying on lattice theory. Then, by observing that this performance gap can be reduced by deactivating parts of the PSs whilst improving both the spectral and energy efficiency, we develop an adaptive RF PS connection network. To resolve the associated hybrid precoding and combining problems, we appropriately adapt Babai's algorithm from the lattice decoding literature. Our simulation results demonstrate the superiority of the proposed scheme both in terms of its spectral and energy efficiency.

中文翻译：

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基于晶格的毫米波混合波束形成


传统的基于混合预编码和组合的收发器需要大量高分辨率射频 (RF) 移相器 (PS)，这会带来高昂的硬件成本和功耗。为了解决上述问题，提出了部分连接的 RF PS 和低分辨率 PS。然而，这些低成本设计的性能限制尚未从理论上进行研究。此外，它们的频谱效率还有改进的空间。为了填补这一知识空白，我们基于格理论导出了在 1 位 PS 约束下最佳预编码器/组合器与混合模拟数字预编码器/组合器之间的均方误差性能差异。然后，通过观察可以通过停用部分 PS 来缩小这种性能差距，同时提高频谱和能源效率，我们开发了一种自适应 RF PS 连接网络。为了解决相关的混合预编码和组合问题，我们适当地采用了格解码文献中的 Babai 算法。我们的仿真结果证明了所提出的方案在光谱和能量效率方面的优越性。