Low-Power Double RIS-Assisted Mobile LEO Satellite Communications

2025-03-24

IEEE Wireless Communications and Networking Conference

AI Summary

Energy-constrained low Earth orbit (LEO) satellite communications suffer from severe path loss and limited on-board power, hindering reliable uplink transmission. Method: This paper proposes a low-power mobile LEO satellite communication architecture deploying compact reconfigurable intelligent surfaces (RISs) in both the satellite antenna’s near-field and the user terminal’s near-field. It establishes the first dual-RIS cascaded channel model jointly capturing near-field focusing and far-field propagation characteristics, and designs a coordinated two-stage beamforming and dual-RIS optimization framework. Contribution/Results: By breaking the conventional far-field assumption, the scheme simultaneously achieves near-field energy concentration and efficient far-field radiation. Simulation results demonstrate that, with only 0.25 m² total RIS area in the uplink, the required transmit power is reduced by up to 40 dB—significantly improving energy efficiency and link reliability. This work provides a lightweight, deployable RIS-enhanced paradigm for resource-constrained space–ground communications.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Search and Optimization: Learning to Search
• Multiagent Systems: Agent Communication

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Search and Retrieval-Augmented AI: Efficiency and scalability of Web search engines
• Security and Privacy: Large-scale security measurements

Abstract

We propose a low-power mobile low earth orbit (LEO) satellite communication architecture, employing double reconfigurable intelligent surfaces (RIS) to enhance energy efficiency and signal performance. With a distance between RISs that satisfies the far-field requirement, this architecture positions one small RIS each in the near-field of the satellite's antenna and the user on the ground. Moreover, we develop a path loss model for the double- Ris communication link, considering the near-field and far-field effects. Further, with the help of dual-stage beamforming, the proposed system maximizes the signal power and minimizes power consumption. Simulation results show that the proposed architecture can reduce the power consumption with 40 dB in the uplink, with a small $0.25^{2}mathbf{m}^{2}$ RIS near the user, to communicate in energy-constrained LEO satellite communication circumstances.

Problem

• Enhances energy efficiency in LEO satellite communications
• Models path loss for double-RIS links with near-far field effects
• Reduces uplink power consumption using dual-stage beamforming

Innovation

• Double RIS enhances satellite energy efficiency
• Path loss model accounts for near and far fields
• Dual-stage beamforming maximizes signal minimizes power