会议时间：2026年7月8日，星期三，上午10:00-12:00
地点：无线谷A11208会议室
报告题目: Multiuser AMP and unsourced random access in cell-free user-centric networks
报告摘要: Unsourced random access refers to the case of a multiple access channel with virtually unlimited users all sharing the same codebook. A user that wishes to access the channel at a given time slot simply picks a codeword and transmits. The primary task of the receiver consists of detecting the active codewords, without knowing a priori who has transmitted them. It turns out that any random access channel (RACH) in current wireless communication systems works in this way. A standard example in this sense is the so-called 2-step RACH of 3GPP. Hence, unsourced random access is not just an interesting information theoretic paradigm, but it is a very fundamental mechanism that allows wireless networks to handle on-off user activity. We consider a cell-free user-centric network, where users are geographically distributed. In this case, the RACH procedure is complicated by the fact that users are served by user-centric clusters, but these clusters can be established only after a user is known to the network (in particular, it's location). Hence, the RACH/unsourced random access for these networks is particularly challenging. We propose a solution based on geographic partition of the random access codebook, in order to establish an a-priori correspondence between codewords and channel statistics. Then, leveraging this a priori information, we propose a novel multiuser approximated message passing algorithm that is able to efficiently detect the active codewords and, as a by-product, also estimate the channel vectors from each active user to the distributed radio units (RUs), and also refine the localization of the active users. In this way, the user-centric clusters for the new users joining the system can be quickly established.
报告人简介:Giuseppe Caire (Fellow, IEEE) was born in Torino in 1965. He received the B.Sc. degree in electrical engineering from the Politecnico di Torino in 1990, the M.Sc. degree in electrical engineering from Princeton University in 1992, and the Ph.D. degree from the Politecnico di Torino in 1994.
He has been a Post-Doctoral Research Fellow with European Space Agency (ESTEC), Noordwijk, The Netherlands, from 1994 to 1995, an Assistant Professor in telecommunications with the Politecnico di Torino, an Associate Professor with the University of Parma, Italy, a Professor with the Department of Mobile Communications, Eurecom Institute, Sophia Antipolis, France, a Professor of electrical engineering with the Viterbi School of Engineering, University of Southern California, Los Angeles. He is currently an Alexander von Humboldt Professor with the Faculty of Electrical Engineering and Computer Science, Technical University of Berlin, Germany. His main research interests are in the field of communications theory, information theory, channel, and source coding with particular focus on wireless communications. He has been a member of German National Academy of Sciences (Leopoldina) since 2024 and American National Academy of Engineering (NAE) since 2026. He received the Jack Neubauer Best System Paper Award from the IEEE Vehicular Technology Society in 2003, the IEEE Communications Society and Information Theory Society Joint Paper Award in 2004, 2011, and 2025, Okawa Research Award in 2006, the Alexander von Humboldt Professorship in 2014, the Vodafone Innovation Prize in 2015, the ERC Advanced Grant in 2018, the Leonard G. Abraham Prize for Best IEEE JSAC Paper in 2019, the IEEE Communications Society Edwin Howard Armstrong Achievement Award in 2020, the 2021 Leibniz Prize of German National Science Foundation (DFG), and the CTTC Technical Achievement Award of the IEEE Communications Society in 2023. He has served on the Board of Governors for the IEEE Information Theory Society from 2004 to 2007, and as an officer from 2008 to 2013. He was the President of the IEEE Information Theory Society in 2011.
