论文标题
通过组合方案的多样性启用低成本物联网设备的URLLC
Enabling URLLC for Low-Cost IoT Devices via Diversity Combining Schemes
论文作者
论文摘要
由于对延迟和可靠性的严格限制与物联网节点的简单电路相结合，支持物联网（IoT）时代的超级可靠的低延迟通信（URLLC）是具有挑战性的。维持URLLC的可靠性水平通常需要多样性，但是与辅助程序相关的额外延迟需要考虑，特别是当交流包括低成本的IoT设备时。本文中，我们将选择组合（SC）和切换和保持组合（SSC）多样性方案作为合理的解决方案，以使非常可靠的低延迟性下行链路通信能够向低成本的物联网设备。我们证明了考虑辅助程序所花费的时间，而传统上没有考虑到它对可靠性绩效的影响。我们表明，有最佳数量的接收天线，这表明在某些条件下，关闭其中的一些，特别是在SC操作下。我们强调了SSC相对于SC的优势，只要正确选择了相关的信噪比阈值。我们建议使用仅依靠长期渠道褪色统计数据的固定阈值，这导致了接近最佳的结果。
Supporting Ultra-Reliable Low-Latency Communication (URLLC) in the Internet of Things (IoT) era is challenging due to stringent constraints on latency and reliability combined with the simple circuitry of IoT nodes. Diversity is usually required for sustaining the reliability levels of URLLC, but there is an additional delay associated to auxiliary procedures to be considered, specially when communication includes low-cost IoT devices. Herein, we analyze Selection Combining (SC) and Switch and Stay Combining (SSC) diversity schemes as plausible solutions for enabling ultra-reliable low-latency downlink communications to low-cost IoT devices. We demonstrate the necessity of considering the time spent in auxiliary procedures, which has not been traditionally taken into account, while we show its impact on the reliability performance. We show there is an optimum number of receive antennas, which suggests that under certain conditions it might be required to turn off some of them, specially under the SC operation. We highlight the superiority of SSC with respect to SC as long the associated Signal-to-Noise Ratio threshold is properly selected. We propose using a fixed threshold relying only on long-term channel fading statistics, which leads to near-optimum results.
