Ultra-reliable low-latency communication enables new use cases for mobile radio networks. The ultra-reliability (UR) regime covers outage probabilities between $10^{-9}$ and $10^{-5}$, obtained under stringent latency requirements. Characterisation of the UR-relevant statistics is difficult due to the rare nature of outage events, but diversity defines the asymptotic behaviour of the small-scale fading distributions' lower tail. The UR-relevant regime in large-scale antenna systems behaves differently from the tail. The generalising local diversity at a certain outage probability shows this difference clearly. For more than four independent antenna elements, the classic diversity overestimates and underestimates the slope of the cumulative density function for weak and strong deterministic channel components, respectively.

翻译：超可靠低时空通信为移动无线电网络提供了新的使用案例。超可靠(UR)制度涵盖根据严格的潜伏要求获得的10-9美元至10-5美元之间的误差概率。由于断流事件的罕见性质,很难确定与UR相关的统计数据的特征,但多样性决定了小规模衰减分布的低尾部的无症状行为。大型天线系统中的超可靠(UR)制度与尾部不同。以某种超值概率普及本地多样性明显显示了这一差异。对于四个以上的独立天线元素而言,典型的多样性高估并低估了脆弱和强势确定性信道组件累积密度功能的坡度。