Statistical CSI based design for intelligent reflecting surface assisted MISO systems

• 作 者: Xiaoling HU Junwei WANG Caijun ZHONG
• 机 构: College of Information Science and Electronic Engineering,Zhejiang University,Hangzhou 310027,China
• 出 处: 中国科学：信息科学（英文版）
• 发表日期: 2020年12期
• 关键词: beamforming IRS MISO statistical CSI ergodic capacity

This paper considers an intelligent reflecting surface(IRS)aided multiple-input single-output communication system,where statistical channel state information(CSI)is exploited for transmit beam-forming and IRS beamforming.A tight upper bound is derived for the ergodic capacity of the system.Based on which,the joint optimization of transmit beam and IRS beam are studied.Depending on whether a line-of-sight path exists between the access point and user,two different cases,namely,Rician fading and Rayleigh fading,are separately treated.Specifically,for the Rician fading case,an iterative algorithm is proposed,which is guaranteed to converge.For the Rayleigh fading case,closed-form designs are obtained for the transmit beam and IRS beam.Simulation results show the proposed beamforming scheme achieves similar performance as the benchmark algorithm requiring instantaneous CSI.