Utility-Driven Joint Time-and-Power Allocation in Energy-Harvesting Cognitive Radio Relay Networks

The increasing number of wireless devices has raised significant global concerns regarding energy efficiency and spectrum scarcity. To address this, wireless energy harvesting technology has emerged as a potential solution. By utilizing conventional radio frequency transmissions, this technology can extend the battery life of mobile devices and improve the operational period of energy-constrained wireless networks. This study focuses on a wireless energy harvesting and information transfer protocol within cognitive radio relay networks. In this setup, an energy-constrained secondary user shares the spectrum and simultaneously harvests energy while assisting with the primary transmission. To optimize the allocation of transmission time and harvested power, a challenging computational problem is formulated. The goal is to enhance the utility of the secondary user. To tackle this computationally hard problem, a heuristic solution based on a joint time-and-power allocation strategy is proposed. This approach achieves an impressive 98.5% accuracy while comparing the utility of the secondary users to the optimal benchmark results.