Hybrid beamforming antenna arrays are a prominent component in communications at millimeter-wave frequencies. Multiple analog beamforming arrays will be used for spatial multiplexing of signals also in hand-held devices. In this letter, we derive the correlation coefficient for signals received by two ideal arrays in simple power angular distribution schemes. The purpose is to develop tools for evaluating over-the-air (OTA) setups for testing of hybrid beamforming devices. We show a few exemplary correlation error evaluations that compare near-field multiprobe OTA setups with a perfect target channel model. Results indicate that the correlation error increases with decreasing range length and channel angular spread. Moreover, larger interarray spacing and subarray sizes increase the correlation error.

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OTA 测试背景下混合波束成形阵列的相关性

混合波束成形天线阵列是毫米波频率通信中的重要组成部分。多个模拟波束成形阵列也将用于手持设备中的信号空间复用。在这封信中，我们推导出了两个理想阵列在简单功率角分布方案中接收到的信号的相关系数。目的是开发用于评估空中 (OTA) 设置以测试混合波束成形设备的工具。我们展示了一些示例性相关误差评估，将近场多探头 OTA 设置与完美的目标通道模型进行比较。结果表明相关误差随着距离长度和信道角扩展的减小而增加。此外，更大的阵列间距和子阵列尺寸会增加相关误差。