Breaking the Interference and Fading Gridlock in Backscatter Communications: State-of-the-Art, Design Challenges, and Future Directions
Bowen Gu, Dong Li, Haiyang Ding, Gongpu Wang, Chintha Tellambura
TL;DR
This paper surveys Backscatter Communication (BackCom) as a low-power solution to IoT energy constraints, focusing on three core challenges: direct-link interference (DLI), mutual interference (MI) among tags, and double-path fading. It systematically reviews state-of-the-art interference-mitigation techniques for DLI (SIC, OSIC, OFDM, frequency shift, polarization, and multi-antenna methods) and MI (OFDMA, TDMA, SDMA, MSMA, tag screening, and novel access strategies), followed by strategies against double-path fading (hybrid active/passive, multi-antenna, power-supply enrichment, relays, and RIS-enabled approaches). The article also outlines open issues and future directions, including deep learning for interference cancellation, AI-driven adaptive control, cross-layer optimization, and constructive interference exploitation, to advance robust, energy-efficient BackCom in AmIoT contexts. Overall, the work provides a comprehensive, comparative view of methods to break interference and fading gridlocks, guiding design choices for scalable, green BackCom systems. The practical impact lies in informing researchers and engineers how to select and integrate techniques to extend BackCom range, reliability, and energy efficiency in real-world IoT deployments.
Abstract
As the Internet of Things (IoT) advances by leaps and bounds, a multitude of devices are becoming interconnected, marking the onset of an era where all things are connected. While this growth opens up opportunities for novel products and applications, it also leads to increased energy demand and battery reliance for IoT devices, creating a significant bottleneck that hinders sustainable progress. At this juncture, backscatter communication (BackCom), as a low-power and passive communication method, emerges as one of the promising solutions to this energy impasse by reducing the manufacturing costs and energy consumption of IoT devices. However, BackCom systems face challenges such as complex interference environments, including direct link interference (DLI) and mutual interference (MI) between tags, which can severely disrupt the efficiency of BackCom networks. Moreover, double-path fading is another major issue that leads to the degraded system performance. To fully unleash the potential of BackComs, the purpose of this paper is to furnish a comprehensive review of existing solutions with a focus on combatting these specific interference challenges and overcoming dual-path fading, offering an insightful analysis and comparison of various strategies for effectively mitigating these issues. Specifically, we begin by introducing the preliminaries for the BackCom, including its history, operating mechanisms, main architectures, etc, providing a foundational understanding of the field. Then, we delve into fundamental issues related to BackCom systems, such as solutions for the DLI, the MI, and the double-path fading. This paper thoroughly provides state-of-the-art advances for each case, particularly highlighting how the latest innovations in theoretical approaches and system design can strategically address these challenges.