Time Switching Based Wireless Powered Relay Transmission with Uplink NOMA

Area of Science:

• Wireless communication networks
• Signal processing
• Energy harvesting technologies

Background:

• Non-orthogonal multiple access (NOMA) offers improved spectrum efficiency over orthogonal multiple access (OMA).
• Challenges exist in deep fading channels for far-end nodes in uplink NOMA networks, impacting spectrum efficiency and throughput.
• Traditional relay cooperative communication increases energy expenditure at the relay node.

Purpose of the Study:

• To propose a time switching based wireless powered relay transmission model for uplink NOMA in energy-constrained IoT networks.
• To enable energy harvesting (EH) from two simultaneously transmitting nodes.
• To optimize relay position for enhanced energy harvesting and reduced signal attenuation.

Main Methods:

• Developed a time switching based wireless powered relay transmission model.
• Incorporated simultaneous wireless information and power transfer (SWIPT) for energy harvesting from two nodes.
• Optimized relay position and time switching factor.

Main Results:

• Derived closed-form expressions for outage probability and overall system throughput.
• Demonstrated superior performance of the proposed NOMA EH scheme compared to traditional EH and OMA schemes.
• Showcased performance gains through optimization of relay position and time switching factor.

Conclusions:

• The proposed wireless powered relay NOMA system with dual-node energy harvesting significantly improves performance in IoT networks.
• Optimizing relay placement and time switching is crucial for maximizing energy harvesting and system throughput.
• This approach offers a viable solution for energy-constrained IoT networks seeking enhanced spectral and energy efficiency.