Hongqin Ke Jindan Xu Wei Xu 0001 Chau Yuen Zhaohua Lu Joint RIS-UE Association and Beamforming Design in RIS-Assisted Cell-Free MIMO Network. 10616-10630 2025 November 73 IEEE Trans. Commun. 11 https://doi.org/10.1109/TCOMM.2025.3585502 db/journals/tcom/tcom73.html#KeXXYL25 streams/journals/tcom