Beamforming technology is widely used in millimeter wave systems to combat path losses, and beamformers are usually selected from a predefined codebook. Unfortunately, the traditional codebook design neglects the beam squint effect, and this will cause severe performance degradation when the bandwidth is large. In this letter, we consider that a codebook with fixed size is adopted in the wideband beamforming system. First, we analyze how beam squint affects system performance when all beams have the same width. The expression of average spectrum efficiency is derived based on the ideal beam pattern. Next, we formulate the optimization problem to design the optimal codebook. Simulation results demonstrate that the proposed codebook deals with beam squint by spreading the beam coverage and significantly mitigates the performance degradation.

中文翻译：

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具有波束斜视的毫米波波束形成系统的性能分析和码本设计


波束形成技术广泛应用于毫米波系统中以对抗路径损耗，波束形成器通常从预定义的码本中选择。不幸的是，传统的码本设计忽略了波束斜视效应，这在带宽较大时会导致严重的性能下降。在这封信中，我们考虑在宽带波束形成系统中采用固定大小的码本。首先，我们分析当所有光束具有相同宽度时光束斜视如何影响系统性能。基于理想波束方向图推导了平均频谱效率的表达式。接下来，我们制定优化问题来设计最佳码本。仿真结果表明，所提出的码本通过扩展波束覆盖范围来处理波束斜视，并显着减轻性能下降。