Exploiting aerial base stations (A-BSs) in conjunction with terrestrial base stations (T-BSs) is an effective solution to provide uniform coverage everywhere, and anytime. However, the addition of A-BSs in an existing terrestrial network would intensify the inter-cell interference to user equipment, leads to a degraded signal-to-interference-ratio. There is a need to exploit inter-cell-interference-coordination (ICIC) scheme in such aerial-terrestrial network. Further, the aerial-terrestrial network requires a multi-layer environment to be modelled in many scenarios. In this study, the authors propose fractional frequency reuse (FFR) scheme as an ICIC scheme for two-layer aerial-terrestrial network. The analytical expression of coverage probability and average rate are derived for the proposed scheme, and compare it with the scheme, where no ICIC is considered in aerial-terrestrial network, and conventional scheme, where only T-BSs are considered. It is shown that the proposed scheme outperforms the no ICIC scheme and conventional scheme. Simulation results are shown to support their analytical results.

中文翻译：

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FFR辅助的两层空中地面网络的建模和性能分析

与地面基站（T-BS）一起开发空中基站（A-BS）是一种有效的解决方案，可随时随地提供统一的覆盖范围。然而，在现有的地面网络中添加A-BS将加剧对用户设备的小区间干扰，导致信噪比降低。需要在这种空中地面网络中利用小区间干扰协调（ICIC）方案。此外，在许多情况下，空中地面网络都需要对多层环境进行建模。在这项研究中，作者提出了分数频率重用（FFR）方案作为两层空中地面网络的ICIC方案。推导了该方案的覆盖概率和平均速率的解析表达式，并将其与该方案进行比较，在空中地面网络中不考虑ICIC的情况，以及在传统方案中仅考虑T-BS的情况。结果表明，所提出的方案优于无ICIC方案和常规方案。显示了仿真结果以支持其分析结果。