AI-Empowered UAV-Assisted Backscatter Localization and ISAC for Zero-Energy IoT: A Comprehensive Survey

This paper addresses the growing need for sustainable, battery-free IoT devices by surveying the convergence of several advanced wireless technologies. Conventional IoT nodes rely on batteries, which limit deployment lifespan and scalability. The authors explore a paradigm shift toward zero-energy IoT, where passive devices harvest energy from ambient or dedicated RF sources and communicate via backscatter communication (BackCom). Because BackCom is limited by weak signals and short range, the paper examines how Unmanned Aerial Vehicles (UAVs) can act as mobile infrastructure to improve coverage and link quality. Furthermore, it integrates Integrated Sensing and Communication (ISAC) to allow these systems to perform localization and environmental sensing simultaneously with data transmission, all optimized through AI-driven techniques.

To organize this complex field, the author employs a PRISMA-informed methodology to review existing literature. The core contribution is a unified taxonomy that categorizes research based on network architecture, specific UAV roles (e.g., mobile carrier, relay, sensing platform), backscatter modes, and the AI techniques used for optimization. By moving beyond a simple paper-by-paper review, the author establishes a cross-layer perspective that connects physical-layer signal processing with network-level mobility and energy constraints.

As 6G and massive IoT deployments approach, the ability to maintain large-scale sensing networks without battery maintenance is critical. This survey provides a roadmap for researchers to understand the trade-offs between communication throughput, sensing accuracy, and UAV flight energy. By highlighting the role of AI in managing the dynamic, coupled nature of these variables, the paper identifies key open challenges—such as the need for realistic channel modeling, trustworthy AI, and hardware-level validation—that must be addressed to move these technologies from conceptual frameworks to practical, large-scale deployments.