Yunfei Chen
Durham University, UK
Yunfei Chen is a Professor of Signal Processing and Communications in the Department of Engineering at the University of Durham in the UK. His main research interests include wireless system design and analysis, non-terrestrial communications, integrated sensing and communications, energy harvesting communications, THz communications, statistical signal processing and machine learning for communications. He is an IEEE Fellow and IET Fellow. He served as editor for the IEEE Transactions on Communications, IEEE Wireless Communications Letters and IEEE Communications Letters, as well as guest editors for special issues in various IEEE and non-IEEE journals. He won several Best Paper awards from the major conferences in wireless communications. He has co-authored more than 400 peer-reviewed journal papers and nearly 150 conference papers, 5 book chapters and one monograph. He was listed as Highly Cited Researcher by Clarivate since 2020.
Movable antenna (MA) can enhance the performance of integrated sensing and communications (ISAC). However, a side effect of moving the antennas is that the propagation field may change during the movement, while most existing works assume either both near-field (NF) or far-field (FF) propagation models for communication users (CUs) and targets. This study considers a more practical scenario where users and targets may be in a mixed near- and far-field environment caused by antenna movements. To evaluate the performance of MA-aided ISAC in mixed-field environments, we formulate an optimization problem to maximize the sum secrecy rate (SSR) of CUs by jointly designing the transmit beamforming and antenna positions at the transmitter. A two-layer algorithm is proposed to iteratively solve this problem using the projected gradient ascent (PGA) method and the Lagrangian dual transform. Simulation results from the solution show that the MA-ISAC in NF outperforms MA-ISAC in the mixed-field with marginal performance gain. Moreover, performance loss may occur using MA if the propagation field changes during the antenna position updates while this is ignored in the design due to outdated channel state information. In some cases, this performance loss is even larger than the performance gain achieved by using MA over those using fixed antenna.