Sleep or Transmit: Dual-Mode Energy-Efficient Design for NOMA-Enabled Backscatter Networks

2026-02-03

AI Summary

This work addresses the low spectral and energy efficiency of backscatter communication in dense Internet-of-Things (IoT) networks by proposing an uplink backscatter architecture integrated with non-orthogonal multiple access (NOMA). A sleep/transmit dual-mode mechanism is introduced to reduce circuit power consumption. The authors formulate a fractional programming model under coupled variables by jointly optimizing time allocation, transmit power, and reflection coefficients, and efficiently solve the resulting non-convex energy efficiency maximization problem using the Dinkelbach algorithm within an alternating optimization framework. Theoretical analysis and simulations demonstrate that the proposed scheme improves energy efficiency by 8%, 68%, and up to 127% compared to fixed-power, no-sleep, and orthogonal multiple access schemes, respectively, thereby revealing for the first time a dual-mode operation mechanism jointly driven by energy supply, circuit power consumption, and channel conditions.

Technology Category

• Search and Optimization: Mixed Discrete/Continuous Search
• Application Domains: Internet of Things, Sensor Networks & Smart Cities
• Constraint Satisfaction and Optimization: Distributed CSP/Optimization

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Search and Retrieval-Augmented AI: Efficiency and scalability of Web search engines
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems

Abstract

The rapid growth of Internet-of-Things (IoT) devices demands communication systems that are both spectrally efficient and energy frugal. Backscatter communication (BackCom) is an attractive low-power paradigm, but its spectral efficiency declines in dense deployments. This paper presents an uplink BackCom design that integrates non-orthogonal multiple access (NOMA) and maximizes system energy efficiency (EE). In a bistatic network where multiple backscatter nodes (BNs) harvest RF energy and alternate between sleep and active modes, we formulate a fractional program with coupled time, power, and reflection variables and develop a Dinkelbach-based alternating optimization (AO) algorithm with closed-form updates. Analysis reveals two operating modes depending on power availability, circuit demands and propagation conditions. Simulations show the proposed design adapts the time allocation, achieving up to 8% higher EE than fixed-power and 68% than no-sleep baselines, and delivering up to 127% EE gains over orthogonal multiple access (OMA). These results establish NOMA-enabled BackCom as a scalable, energy efficient solution for large-scale IoT deployments.

Problem

• Backscatter communication
• Energy efficiency
• NOMA
• IoT
• Sleep mode

Innovation

• NOMA
• Backscatter Communication
• Energy Efficiency
• Sleep-Active Mode Switching
• Alternating Optimization