Transmissive RIS-Assisted Vehicular Direct-to-Satellite Communications: Opportunities, Limitations, and Comparison with Phased Arrays

2026-08-29

AI Summary

研究了透射型RIS辅助架构在车载直连卫星通信中的应用，与相控阵进行比较，探讨了各自适用场景及优缺点。

Abstract

This article studies transmissive reconfigurable intelligent surface (RIS)-assisted architectures. It compares them with electronically steered phased arrays for the deployment of vehicular direct-to-satellite (D2S) communications in future satellite networks. Rather than treating RIS as a direct replacement for phased arrays, we clarify the operating regimes in which RIS can serve as a low-power wavefront-shaping aperture and those in which phased arrays remain preferable because of their high gain and mature beam-tracking capability. Moreover, phased arrays can support multi-beam operation, which is particularly beneficial for dual connectivity and seamless handover. We distinguish analog, digital, and hybrid phased arrays, discuss the relationship between transmissive RIS and reconfigurable transmitarrays, and highlight practical profile, tracking, and link-budget constraints for mobile terminals. The comparison shows that passive RIS offers attractive power efficiency and aperture scalability, active RIS can partially improve the link budget, and phased arrays remain preferable for high-throughput.

Problem

• transmissive RIS
• vehicular direct-to-satellite communications
• phased arrays
• wavefront-shaping aperture
• beam-tracking capability

Innovation

• transmissive RIS
• phased arrays
• vehicular direct-to-satellite communications
• wavefront-shaping aperture
• multi-beam operation