论文标题
启用NLOS LEO卫星通信与可重构的智能表面
Enabling NLoS LEO Satellite Communications with Reconfigurable Intelligent Surfaces
论文作者
论文摘要
低地球轨道（LEO）卫星通信（SATCOM）被认为是在蜂窝网络中提供不间断服务的有前途解决方案。但是，在城市场景中，LEO卫星和地面用户之间的视线（LOS）链接很容易被阻止。在本文中，我们建议在非线（NLOS）频道中启用Leo Satcom，作为与可重构的智能表面（RISS）相对应的与Urban Canyons用户链接相对应的。首先，我们得出了卫星 - ris-user链接的近场信号模型。然后，我们提出了两次部署，以改善RIS辅助链接的覆盖范围：向下倾斜位于建筑物顶部的RIS，并考虑与RISS的部署，位于相对建筑物的顶部。仿真结果表明，使用LEO SATCOM中使用RISS来克服城市峡谷的障碍的有效性。还提供了有关最佳倾斜角度和通过部署额外RI提供的覆盖范围扩展的见解。
Low Earth Orbit (LEO) satellite communications (SatCom) are considered a promising solution to provide uninterrupted services in cellular networks. Line-of-sight (LoS) links between the LEO satellites and the ground users are, however, easily blocked in urban scenarios. In this paper, we propose to enable LEO SatCom in non-line-of-sight (NLoS) channels, as those corresponding to links to users in urban canyons, with the aid of reconfigurable intelligent surfaces (RISs). First, we derive the near field signal model for the satellite-RIS-user link. Then, we propose two deployments to improve the coverage of a RIS-aided link: down tilting the RIS located on the top of a building, and considering a deployment with RISs located on the top of opposite buildings. Simulation results show the effectiveness of using RISs in LEO SatCom to overcome blockages in urban canyons. Insights about the optimal tilt angle and the coverage extension provided by the deployment of an additional RIS are also provided.
