Localization and tracking of ambient RF sources with analog backscatter tags

Abstract

Analog backscatter communication enables ultra low-power and low-cost wireless connectivity, making it a promis ing alternative to traditional RFID systems. Although analog backscatter systems offer simplicity, they are by design less capable compared to their digital backscatter counterparts. A key drawback of existing analog backscatter systems is their single-tag operation, which poses limitations for applications that require multiple tags to function simultaneously. In this paper, we propose a novel low-cost analog backscatter system that allows multiple tags to sense the channel concurrently, thereby enabling signal strength-based localization and tracking of ambient RF sources. The ability to localize RF sources is essential for interference management, security, and optimization of wireless networks, particularly in dynamic environments. We evaluate our system in indoor settings, and demonstrate localization accuracy of RF sources with an average error of 20 cm in a 3 m range, without requiring calibration. Our system is also capable of tracking RF sources with an average speed up to 0.6 m/s with an average power consumption of 526 µW, making it a promising solution for real-time and energy-constrained applications.