Outage Analysis for Active Reconfigurable Intelligent Surface-Enhanced Wireless Powered Communication Networks

TL;DR

This work tackles the double-fading challenge in RIS-aided wireless powered communication by introducing an active RIS that amplifies reflected signals. It develops a two-phase system model with energy harvesting and RIS-based beamforming, and derives a closed-form outage probability under Rayleigh fading while accounting for active-RIS noise. The results show that increasing the number of active RIS elements $M$ and the amplification gain $\rho$ reduces outage and lowers the required transmit power, enabling more energy-efficient operation. These insights offer practical design guidelines for reliable, energy-constrained wireless links in 6G IoT and autonomous-device scenarios.

Abstract

Wireless powered communication (WPC) involves the integration of energy harvesting and data transmission. This allows devices to communicate without constant battery replacements or wired power sources. Reconfigurable intelligent surfaces (RISs) can dynamically manipulate radio signals. In this paper, we explore the use of active elements to mitigate double-fading challenges inherent in RIS-aided links. We enhance the reliability performance for an energy-constrained user by combining active RIS and WPC. The theoretical closed-form analysis, which includes transmission rate, harvested energy, and outage probability, provides valuable insights that inform parameter selection.

Figures (2)

• Figure 1: Active RIS-Enhanced WPC Network.
• Figure 2: Outage probability vs. Number of active elements ($M$) for different amplification gain ($\rho$)