This letter analyzes the impact of interuser distance and angular separation on the channel correlation and achievable sum-rate for a massive multiple-input–multiple-output (MIMO) system in non-line-of-sight (NLOS) conditions. The investigation is based on outdoor measurements on a channel sounding system capturing the dynamic channel of two user arrays. The letter analyzes correlation and sum-rate with varying interuser distance and angular separation of dominant beams toward the users. A large span of correlation and sum-rate values are found across the range of distances and angular separation. The investigation shows a moderate link between interuser distance and correlation, but a strong impact on correlation is found only for low angular separation of the users. The results of this NLOS scenario suggest that a distance-based criteria alone is not sufficient to accurately model shared clusters and their correlation.

中文翻译：

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室外测量的大规模 MIMO 信道中的多用户相关性和总和率

这封信分析了用户间距离和角分离对非视距 (NLOS) 条件下大规模多输入多输出 (MIMO) 系统的信道相关性和可实现总速率的影响。该调查基于对捕获两个用户阵列的动态信道的信道探测系统的室外测量。这封信分析了不同用户间距离和主波束朝向用户的角度分离的相关性和总和率。在距离和角间距范围内发现了大范围的相关性和总和率值。调查显示用户间距离和相关性之间存在中等联系，但仅在用户的低角度分离时发现对相关性的强烈影响。