TY - JOUR
T1 - Ergodic Rate Analysis of Reconfigurable Intelligent Surface-Aided Massive MIMO Systems with ZF Detectors
AU - Zhi, Kangda
AU - Pan, Cunhua
AU - Ren, Hong
AU - Wang, Kezhi
N1 - Funding information: This work was supported in part by the National Key Research and Development Project under Grant 2019YFE0123600, National Natural Science Foundation of China (62101128) and Basic Research Project of Jiangsu Provincial Department of Science and Technology (BK20210205).
PY - 2022/2
Y1 - 2022/2
N2 - This letter investigates the reconfigurable intelligent surface (RIS)-aided massive multiple-input multiple-output (MIMO) systems with a two-timescale design. First, the zero-forcing (ZF) detector is applied at the base station (BS) based on instantaneous aggregated channel state information (CSI), which is the superposition of the direct channel and the cascaded user-RIS-BS channel. Then, by leveraging the channel statistical property, we derive the closed-form ergodic achievable rate expression. Using a gradient ascent method, we design the RIS passive beamforming relying only on the long-term statistical CSI. We prove that the ergodic rate scales on the order of O(log2 (MN)), where M and N denote the number of BS antennas and RIS elements, respectively. We also prove the striking superiority of the considered RIS-aided system with ZF detectors over the RIS-free systems and RIS-aided systems with maximum-ratio combining (MRC).
AB - This letter investigates the reconfigurable intelligent surface (RIS)-aided massive multiple-input multiple-output (MIMO) systems with a two-timescale design. First, the zero-forcing (ZF) detector is applied at the base station (BS) based on instantaneous aggregated channel state information (CSI), which is the superposition of the direct channel and the cascaded user-RIS-BS channel. Then, by leveraging the channel statistical property, we derive the closed-form ergodic achievable rate expression. Using a gradient ascent method, we design the RIS passive beamforming relying only on the long-term statistical CSI. We prove that the ergodic rate scales on the order of O(log2 (MN)), where M and N denote the number of BS antennas and RIS elements, respectively. We also prove the striking superiority of the considered RIS-aided system with ZF detectors over the RIS-free systems and RIS-aided systems with maximum-ratio combining (MRC).
KW - intelligent reflecting surface (IRS)
KW - massive MIMO
KW - Reconfigurable intelligent surface (RIS)
KW - statistical CSI
KW - ZF
UR - http://www.scopus.com/inward/record.url?scp=85120074074&partnerID=8YFLogxK
U2 - 10.1109/LCOMM.2021.3128904
DO - 10.1109/LCOMM.2021.3128904
M3 - Article
AN - SCOPUS:85120074074
SN - 1089-7798
VL - 26
SP - 264
EP - 268
JO - IEEE Communications Letters
JF - IEEE Communications Letters
IS - 2
ER -