时间：2026年7月8日 星期三 10:00-11:00
地点：无线谷2322
Presenter:
Liang LIU, The Hong Kong Polytechnic University
Abstract:
Beyond diagonal reconfigurable intelligent surface (BD-RIS) refers to a family of RIS architectures characterized by scattering matrices not limited to being diagonal and enables higher wave manipulation flexibility and large performance gains over conventional (diagonal) RIS. However, whether BD-RIS aided network is able to deliver more data volume compared to conventional RIS aided network is still questionable, because far more time may be wasted to estimate the massive channel coefficients associated with the off-diagonal entries of the BD-RIS scattering matrix. Amazingly, for the first time in the literature, this talk will show that the uplink channel estimation overhead in BD-RIS assisted multi-antenna and multi-user systems is actually of the same order as that in the conventional RIS assisted systems. This fantastic result is based on some channel property that has not been revealed before. The message is that we can benefit from the non-diagonal scattering matrix design at a channel estimation cost similar to that in conventional RIS aided network.
Bio:
Dr. Liang LIU is an associate professor in the Department of EEE at PolyU. His research interests include wireless communications and networking, advanced signal processing and optimization techniques, and Internet-of-Things (IoT).
Dr. Liang LIU is an IEEE Fellow. He is an IEEE ComSoc Distinguished Lecturer for the class of 2025-2026. He is the recipient of the 2021 IEEE Signal Processing Society Best Paper Award, the 2017 IEEE Signal Processing Society Young Author Best Paper Award, the Best Student Paper Award for 2022 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), and the Best Paper Award for 2011 International Conference on Wireless Communications and Signal Processing (WCSP). He was listed in Highly Cited Researchers, also known as World's Most Influential Scientific Minds, by Clarivate Analytics (Thomson Reuters) in 2018. He is an editor for IEEE Transactions on Wireless Communications, and was a leading guest editor for IEEE Wireless Communications special issue on "Massive Machine-Type Communications for IoT". He is a co-author of the book "Next Generation Multiple Access" published at Wiley-IEEE Press.
