Passive DSSS: Empowering the Downlink Communication for Backscatter Systems


Songfan Li, Hui Zheng, Chong Zhang, Yihang Song, Shen Yang, Minghua Chen, and Li Lu, University of Electronic Science and Technology of China (UESTC); Mo Li, Nanyang Technological University (NTU)


The uplink and downlink transmissions in most backscatter communication systems are highly asymmetric. The downlink transmission often suffers from its short range and vulnerability to interference, which limits the practical application and deployment of backscatter communication systems. In this paper, we propose passive DSSS to improve the downlink communication for practical backscatter systems. Passive DSSS is able to increase the downlink signal-to-interference-plus-noise ratio (SINR) by using direct sequence spread-spectrum (DSSS) techniques to suppress interference and noise. The key challenge lies in the demodulation of DSSS signals, where the conventional solutions require power-hungry computations to synchronize a locally generated spreading code with the received DSSS signal, which is infeasible on energy-constrained backscatter devices. Passive DSSS addresses such a challenge by shifting the generation and synchronization of the spreading code from the receiver to the gateway side, and therefore achieves ultra-low power DSSS demodulation. We prototype passive DSSS for proof of concept. The experimental results show that passive DSSS improves the downlink SINR by 16.5 dB, which translates to a longer effective downlink range for backscatter communication systems.

NSDI '22 Open Access Sponsored by
King Abdullah University of Science and Technology (KAUST)

Open Access Media

USENIX is committed to Open Access to the research presented at our events. Papers and proceedings are freely available to everyone once the event begins. Any video, audio, and/or slides that are posted after the event are also free and open to everyone. Support USENIX and our commitment to Open Access.

@inproceedings {278296,
author = {Songfan Li and Hui Zheng and Chong Zhang and Yihang Song and Shen Yang and Minghua Chen and Li Lu and Mo Li},
title = {Passive {DSSS}: Empowering the Downlink Communication for Backscatter Systems},
booktitle = {19th USENIX Symposium on Networked Systems Design and Implementation (NSDI 22)},
year = {2022},
isbn = {978-1-939133-27-4},
address = {Renton, WA},
pages = {913--928},
url = {},
publisher = {USENIX Association},
month = apr

Presentation Video