Enhanced FSK-modulated Ambient Backscatter Communication System

Backscatter communication (Backcom) technology is rapidly developing for deployment in Internet-of-Things (IoT) applications due to its low cost and potential for battery-free operation. In this work, we show that with proper processing at the Backcom receiver the performance of ambient Backcom, with frequency-shift-keying (FSK) based modulation, can be significantly improved compared to the current state of the art. Employing existing ambient radio frequency (RF) signals like TV, FM, Wi-Fi, cellular, etc. as carriers to eliminate dedicated carrier generator, namely ambient Backcom, can massively reduce system costs. However, this compromises to link performance, e.g., data rates and communication range, can be significant and therefore limit its application. Our proposed system is validated using ambient FM signals and 40 kHz bandwidth digital signals in both simulation and experimental environments, achieving zero-error communication with 4m distance between tag and receiver at 200 bps.