Faculty Candidate Seminar

Robust IoT Communication and Sensing with Extreme Efficiency

Renjie ZhaoPh.D. CandidateUniversity of California, San Diego
3725 Beyster BuildingMap

Zoom link for remote participants, passcode:  057610


The Internet of Things (IoT) has the potential to revolutionize how we live and work by bridging the physical and digital worlds, but the current battery-based architecture limits its scalability and poses environmental challenges. To overcome these limitations, the next trillion IoT devices should be battery-free, maintenance-free, and low-cost, which requires a fundamental rethink of wireless networking, a core component of IoT. In this talk, I will share my research on developing new systems and radio architectures for battery-free IoT communication and sensing that significantly improve energy efficiency, reliability, and cost.

My talk will begin with a focus on how to enable extremely low power communication for Consumer IoT. I will discuss new radio architectures that reduce power consumption by orders of magnitude, as well as an asymmetric communication system architecture that can reuse pervasively deployed Wi-Fi devices as infrastructure to connect IoT devices to the Internet. This approach brings battery-free IoT to consumers’ homes without requiring new wireless infrastructures.

Moving on to Industrial IoT, I will explain how to address the critical issue of high reliability through the development of a new magnetic RFID system and robust RFID localization design. I will explain how the long-range magnetic RFID system can achieve two orders of magnitude lower object identification error, solving the reliability problem that has hindered the widespread adoption of battery-free RFID systems in the industry.

Finally, I will briefly discuss my other contributions, including the creation of the first massive MIMO millimeter-wave software-defined radio and the development of a wireless brain-machine interface. These programmable experimental platforms open up exciting opportunities for next-generation IoT applications.

By building upon past innovations, I will discuss the exciting opportunities presented by next-generation technologies such as battery-free IoT, the Internet of Bodies, and experimental infrastructures for wireless systems. These innovations offer a promising avenue toward a sustainable and scalable IoT future.


Renjie Zhao is a Ph.D. candidate in the ECE department at the University of California San Diego, currently in his 5th year of study under the guidance of Professor Xinyu Zhang. Prior to pursuing his Ph.D., Renjie received his B.E. degree from Shanghai Jiao Tong University in 2018. Renjie’s research interests are centered around wireless systems and networking, with a particular focus on next-generation cellular networks, IoT, and mobile and ubiquitous computing. Renjie’s research has been published in several top conferences, including ACM SIGCOMM, MobiCom, and USNIEX NSDI. In recognition of his work on massive MIMO millimeter-wave software radio, Renjie was awarded the Best Paper Award at ACM MobiCom 2020. His work on this project has also been highlighted by ACM GetMobile, the top pick of the ACM SIGMOBILE area.


Cindy Estell

Student Host

Hsun-Wei Cho

Faculty Host

Kang Shin