Beamspace multiple-input multiple-output (B-MIMO) provides a promising solution for reducing the number of required expensive radio frequency (RF) chains without obvious performance loss. However, the high computational complexities of beam selection algorithms prohibits their practical applications in 5G millimeter wave (mmWave) massive MIMO communication systems. Reviewing existing beam selection procedures and using the matrix perturbation theory, the complexity reduction on beam selection for beamspace MIMO is considered in this letter. Two beam selection algorithms, one for B-MIMO systems with classic zero-forcing (ZF) precoder and the other for the systems with QR precoder are proposed. Theoretical analyses and numerical simulations all show that the proposed beam selection algorithms possess a much lower complexity than conventional ones.

中文翻译：

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波束空间MIMO系统波束选择算法的复杂度降低

波束空间多输入多输出 (B-MIMO) 提供了一种很有前景的解决方案，可以减少所需的昂贵射频 (RF) 链的数量，而不会造成明显的性能损失。然而，波束选择算法的高计算复杂性阻碍了它们在 5G 毫米波 (mmWave) 大规模 MIMO 通信系统中的实际应用。回顾现有的波束选择程序并使用矩阵微扰理论，在这封信中考虑了波束空间 MIMO 波束选择的复杂性降低。提出了两种波束选择算法，一种用于具有经典迫零 (ZF) 预编码器的 B-MIMO 系统，另一种用于具有 QR 预编码器的系统。理论分析和数值模拟都表明，所提出的光束选择算法比传统算法的复杂度低得多。