Bit Alignment for Bluetooth Backscatter Communication
Abstract
In this paper, we propose Bitalign, a Bluetooth backscatter system that can make use of uncontrolled ambient signals as excitations and deliver high throughput for multimedia streaming applications. To do so, we identify several backscatter bottlenecks and employ a set of techniques to considerably boost backscatter throughput. In particular, we introduce an excitor-aware synchronization that can efficiently distinguish various ambient signals and accurately decide where to modulate. And we further propose a matching-based synchronization method with higher synchronization accuracy. In addition, to make the Bluetooth system truly compatible with the commercial Bluetooth device, we propose the header reconstruction method to work well with the whitened excitation packet. To verify the proposal, we implement a tag prototype using FPGAs and conduct extensive experiments in various conditions. Results show that the minimum BER of Bitalign is 0.5%, which is 60 times better than that of FreeRider, a state-of-the-art Bluetooth system. And the maximal theoretical throughput of Bitalign is 1.98 Mbps, which can reliably support 720p video transmissions of up to 30 fps, manifesting great potential for future battery-free multimedia streaming.
Authors
Zhanxiang Huang, Yuan Ding , Dapeng Oliver Wu, and Wei Gong
Publication
IEEE Transactions on Mobile Computing（CCF A）
Keywords
Backscatter, Bluetooth, Internet-of-Things, Multimedia
