Wireless Information and Power Transfer with Full Duplex Relaying (1409.3904v1)

Abstract: We consider a dual-hop full-duplex relaying system, where the energy constrained relay node is powered by radio frequency signals from the source using the time-switching architecture, both the amplify-and-forward and decode-and-forward relaying protocols are studied. Specifically, we provide an analytical characterization of the achievable throughput of three different communication modes, namely, instantaneous transmission, delay-constrained transmission, and delay tolerant transmission. In addition, the optimal time split is studied for different transmission modes. Our results reveal that, when the time split is optimized, the full-duplex relaying could substantially boost the system throughput compared to the conventional half-duplex relaying architecture for all three transmission modes. In addition, it is shown that the instantaneous transmission mode attains the highest throughput. However, compared to the delay-constrained transmission mode, the throughput gap is rather small. Unlike the instantaneous time split optimization which requires instantaneous channel state information, the optimal time split in the delay-constrained transmission mode depends only on the statistics of the channel, hence, is suitable for practical implementations.

• The paper demonstrates that leveraging dual antennas for energy harvesting significantly improves performance, especially under low source power conditions.
• It derives analytical expressions for throughput metrics across instantaneous, delay-constrained, and delay-tolerant transmission modes.
• The study shows that optimal time allocation and DF protocols yield superior throughput compared to HD systems, underscoring practical deployment benefits.

Insights into Wireless Information and Power Transfer with Full Duplex Relaying

The paper "Wireless Information and Power Transfer with Full Duplex Relaying" presents a detailed paper on utilizing full-duplex (FD) capabilities in dual-hop wireless systems that are constrained by energy. These systems leverage the capability of a relay node to harvest energy from radio frequency (RF) signals emitted by the primary source. The authors explore the potential integrations of information and power transfer through the adoption of both amplify-and-forward (AF) and decode-and-forward (DF) protocols, establishing a framework that extends beyond conventional energy-constrained communication methods.

Key Contributions

The authors of this paper make several substantive contributions to the field of simultaneous wireless information and power transfer (SWIPT) using full-duplex technologies. The main findings and contributions include:

1. Dual Antenna Utilization: The paper highlights the advantages of employing both antennas at the relay station for energy harvesting, proposing that this configuration generally outperforms the single antenna alternative, especially when the source transmit power is lower.
2. Throughput Metrics: Through a series of analytical expressions derived for three distinct communication modes (instantaneous transmission, delay-constrained transmission, and delay-tolerant transmission), the authors quantify the throughput performance. They provide closed-form results for the outage probability in delay-constrained modes and the achievable rate in delay-tolerant scenarios.
3. Optimal Time Split: The research determines the optimal allocation of time between energy harvesting and communication phases. For the AF and DF protocols, various optimization scenarios are considered, with the numerical results indicating that DF relaying consistently offers better throughput.
4. Full-Duplex versus Half-Duplex: An important aspect of this investigation is the comparison between FD and half-duplex (HD) relaying systems. The numerical analysis illustrates that subject to proper optimization, FD architectures can significantly enhance system throughput over their HD counterparts.
5. Practical Implementation Aspects: The authors note the viability of delay-tolerant modes in real-world applications, where global instantaneous channel state information (CSI) might be difficult to acquire due to overhead and practical constraints. This approach allows significant throughput gains using channel statistics alone, a key benefit in practical deployments.

Implications and Future Directions

The implications of this work extend to both practical and theoretical domains within the context of next-generation wireless networks and energy management. Practically, the significant throughput gains associated with FD technologies underscore their potential in enhancing the efficiency of future cooperative networks reliant on energy harvesting. Theoretically, the paper opens new pathways in optimizing time allocation for dual function antennas, offering a benchmark for future research in wireless communication architectures.

Moving forward, this paper hints at intriguing avenues for development, such as the exploration of advanced loopback interference cancellation techniques to further push the boundaries of FD relaying system capabilities. Additionally, cross-layer designs that incorporate network-level considerations into relay selection and scheduling strategies could provide additional layers of performance enhancement.

In conclusion, this paper presents a comprehensive investigation into the domain of wireless power and information transfer, building a solid, quantitative foundation that highlights the benefits and feasibility of full-duplex relaying in RF energy harvesting scenarios. As such, it serves as a valuable reference for researchers aiming to harness the full potential of FD technologies in sustainable wireless communication systems.