Speaker:Â Jingyi Liao, PhD Candidate from Aalto University, Finland
Date: August 7, 2025
Time: 1:30pm
Location: E5 5047
Hosted by the Communications Security (ComSec) Lab
All are welcome!
Abstract:
The Internet of Things (IoT) is expected to interconnect billions of low-cost, energy-constrained devices, necessitating scalable and energy-efficient connectivity solutions. In response, the 3rd Generation Partnership Project (3GPP) has initiated a study on Ambient IoT (AIoT), aiming to support massive machine-type communications (mMTC) by employing backscatter technology in licensed cellular bands. The current 3GPP approach relies on continuous wave (CW) carriers transmitted by cellular infrastructure to interrogate passive tags. While this enables higher data rates, it incurs significant power consumption, requires dedicated spectrum, and introduces hardware complexity.
In this talk, we present a low-power, low-complexity alternative that leverages ambient cellular signals—already present in the environment—as the illumination source for backscatter communication. The backscatter tag modulates information using frequency-shift keying (FSK), which appears as an additional multipath component in the cellular channel. We demonstrate, through a proof-of-concept implementation, how existing receiver infrastructure—specifically, the channel estimation modules in base stations and user equipment—can be repurposed to decode the backscattered signal with minimal modifications and no additional hardware. This receiver-centric approach eliminates the need for dedicated CW sources and reduces system complexity, providing a practical and energy-efficient pathway for scalable AIoT deployment.
Biography:
Jingyi Liao received her B.Eng. degree in Electronic Engineering in 2018 and her M.Eng. degree in Information and Communication Engineering in 2021, both from the University of Electronic Science and Technology of China. She is currently pursuing a Ph.D. in the Department of Information and Communication Engineering at Aalto University. Her research focuses on signal processing and performance analysis in ambient backscatter communication systems.