Vehicular Communication Based on RIS-Assisted Source: RIS-Relay Versus Energy Harvesting Relay
Baofeng Ji, Saibing Wang, Hongtao Chen, Xin Jin, Sheng Zeng, Xiaohui Song, Huitao Fan
Abstract
In this paper, we propose two vehicular communication system models based on Reconfigurable Intelligent Surface (RIS)-assisted sources. Specifically, we assume two scenarios: RIS-Relay aided RIS-assisted source and Relay aided RIS-assisted source, where the relay employs the Power Splitter (PS) to divide the received signal into information transmission and energy harvesting parts. Moreover, both scenarios consider whether a direct link exists. We derive in detail precise approximate closed-form expressions for the outage probability in various vehicular communication scenarios under Nakagami-m channels, and conduct asymptotic analysis of the outage probability to gain further insights. Finally, we validate all the analytical results through simulations, demonstrating the accuracy of the expressions we derived. The simulation results indicate that system and channel parameters significantly influence system performance. Additionally, through comparison, we find that the system with RIS-assisted source and RIS-Relay outperforms system where the RIS is used solely as transmitter or relay, as well as the system with RIS-assisted source and energy harvesting relay.