Abstract

Spectrum sharing provides a rapid migration pathway toward 5G by enabling the coexistence of 4G LTE and 5G new radio (NR) that share the same spectrum. Due to significant differences in the LTE and 5G-NR air interfaces, several enablers are required to facilitate the spectrum sharing. In this study, we explore the coexistence features and investigate their impacts on network performance. For static and dynamic spectrum sharing scenarios, we assess the impacts of different spectrum sharing ratios, user ratios, MIMO configurations, mixed numerology profiles and traffic patterns on the user throughput and network capacities of spectrum sharing networks, compared with the LTE only and 5G-NR only networks with exclusive spectrum access. The key results show that spectrum sharing leads to a marginal capacity gain over LTE only network and achieves considerably lower capacity than the 5G-NR only network. Also, the results show that mixed numerology profiles between the LTE and 5G-NR lead to capacity losses due to inter-numerology interference. In addition, user and spectrum sharing ratios between LTE and 5G-NR have critical impacts on performance. Reduced spectrum per device as the number of 5G devices increases, higher signaling overhead and higher scheduling complexity are other limiting factors for spectrum sharing networks. The results show limited capacity benefits and reinforce spectrum sharing between LTE and 5G-NR as mainly an evolutionary path to accommodate 5G users in the same LTE spectrum while migrating to the fully-fledged 5G networks. For significant capacity increase, other features such as carrier aggregation, overlay of small cells and higher order MIMO would need to be incorporated into the network.

中文翻译：

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LTE 和 5G-NR 共存的频谱共享

摘要

频谱共享通过实现共享相同频谱的 4G LTE 和 5G 新无线电 (NR) 的共存，提供了向 5G 的快速迁移途径。由于 LTE 和 5G-NR 空中接口存在显着差异，需要多种推动因素来促进频谱共享。在本研究中，我们探索共存特征并研究它们对网络性能的影响。对于静态和动态频谱共享场景，我们与仅 LTE 和 5G 相比，评估了不同频谱共享比率、用户比率、MIMO 配置、混合参数配置文件和流量模式对频谱共享网络的用户吞吐量和网络容量的影响。仅限 NR 网络，具有独占频谱访问权限。主要结果表明，与仅 LTE 网络相比，频谱共享带来了边际容量增益，并且实现的容量比仅 5G-NR 网络低得多。此外，结果还表明，LTE 和 5G-NR 之间的混合参数配置文件会因参数间干扰而导致容量损失。此外，LTE 和 5G-NR 之间的用户和频谱共享比对性能也有关键影响。随着 5G 设备数量的增加，每台设备的频谱减少、更高的信令开销和更高的调度复杂性是频谱共享网络的其他限制因素。结果显示容量优势有限，并加强了 LTE 和 5G-NR 之间的频谱共享，这主要是在同一 LTE 频谱中容纳 5G 用户同时迁移到成熟的 5G 网络的演进路径。为了显着增加容量，需要将其他功能（例如载波聚合、小蜂窝覆盖和高阶 MIMO）纳入网络中。